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Nutrition

Training lays down the stimulus, nutrition supplies the building blocks. Use the calorie calculator for your energy needs and the protein calculator below for your protein target — and stick to these basic principles for the quality of your nutrition.

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Scan the barcode on a package and instantly see what's in it. Add it to your day and follow your calories, protein, carbs and fat.

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01

Protein at every meal

Chicken, eggs, quark, lentils or tofu at every meal keeps you full and supplies the building blocks for muscle recovery.

02

Unprocessed carbohydrates

Oats, whole-wheat pasta, potatoes and fruit are good sources of energy for heavy training.

03

Healthy fats

Olive oil, nuts, avocado and fatty fish provide the fats you need for hormones and for vitamin absorption.

04

Vegetables at every meal

Vegetables provide fiber, vitamins and minerals. Eat them at every meal for the quality of your nutrition.

Calculator 6 / 7

Protein Calculator

Protein is the macronutrient you can least afford to skimp on when strength training. Calculate how many grams you need per day for your goal, and how to divide that across your eating occasions.

kg

Goal

Above roughly 2.0 g per kilo, extra protein adds hardly any further muscle growth according to the research.

Eating pattern

Alternate meat, fish, eggs and dairy with beans and lentils.

×

Protein per day

125–156

g

1.8 g per kilogram of body weight

Per eating occasion (4×)

35 g

The ISSN names 20 to 40 g per meal as a guideline. If your result is well above that, spread your protein over more eating occasions.

What 35 g looks like

Low-fat quark 250 g25 g
Chicken breast 150 g35 g
Eggs 2 pieces13 g
Salmon fillet 150 g31 g
Tempeh 150 g28 g
Lentils, cooked 200 g18 g
How much protein do I really need?

For people who strength train, 1.6 to 2.0 grams of protein per kilogram of body weight per day is enough for muscle building and recovery according to the research (ISSN, 2017; Morton et al., 2018). More usually brings no extra gain in muscle growth. During a calorie deficit, more can be useful to preserve muscle mass; see the protein calculator for your goal.

Should I spread my protein over the day?

That makes sense. The ISSN names about 0.25 g of protein per kilo of body weight per serving, or 20 to 40 g, and recommends spreading the servings evenly across the day, roughly every 3 to 4 hours.

Can I get enough protein without meat?

Certainly. Legumes, tofu, tempeh, quinoa, eggs and dairy together provide more than enough protein, even on a vegetarian or mostly plant-based diet — just make sure to combine a varied mix of sources.

Is too much protein harmful?

For people with healthy kidneys, a higher protein intake is generally safe. If you have existing kidney problems, it is advisable to talk to a doctor before significantly increasing your intake.

A sample day

Breakfast

Oatmeal with quark, banana, cinnamon and a scoop of peanut butter

~520 kcal · 32 g protein
Lunch

Whole-wheat wrap with chicken breast, hummus, bell pepper and spinach

~610 kcal · 38 g protein
Dinner

Salmon with sweet potato and roasted broccoli in olive oil

~680 kcal · 41 g protein
Post-workout snack

Greek yogurt with walnuts and a handful of blueberries

~290 kcal · 20 g protein

Water and hydration

As a rule of thumb, count on roughly 30-35 ml of water per kilogram of body weight per day, and more on training days. In longer endurance efforts, a fluid deficit of more than 2% of body weight reduces performance; for strength it is less clear. While exercising, the 2015 international consensus advises drinking to thirst. The water calculator calculates your needs for today, including training and warm weather.

Deep dive

What does the research say?

Each block relies on European guidelines, Cochrane reviews, meta-analyses or randomised trials. The sources are listed under each block. Click a block to open it.

This is general information, not medical advice. Always discuss your blood values with your doctor.

01

Heart and cholesterol

LDL, HDL, non-HDL, Lp(a), diabetes, how much influence you have, omega-3, salt and blood pressure.

8 topics

Evidence: strongCochrane review

Cholesterol: the basics and saturated fat

What LDL is and what cutting saturated fat really does.

  1. 1
    LDL is a marker, not the whole story

    LDL cholesterol carries cholesterol through your blood and is the value doctors look at first. HDL and triglycerides complete the picture. Your numbers are a snapshot to discuss with your doctor, not something a website can judge.

  2. 2
    Less saturated fat helps the heart a little

    A Cochrane review of randomised trials (Hooper et al., 2020) found that cutting saturated fat lowers the risk of cardiovascular events, with no clear effect on total mortality during the studies. The effect is small, but relevant.

  3. 3
    What you replace it with matters

    The benefit was mainly seen in studies where saturated fat was replaced by polyunsaturated fat, such as in nuts, fatty fish and vegetable oils. Studies that simply cut fat did less well.

In practice

In practice: swap part of your butter, fatty cheese and fatty cold cuts for olive oil, nuts and fatty fish.

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Sources

Evidence: strongguidelines and meta-analyses

Cholesterol: LDL, non-HDL and apoB, which target counts?

What your blood test measures, the European targets and why LDL alone is not always enough.

  1. 1
    First: what does your blood test measure?

    A standard lipid profile gives total cholesterol, LDL, HDL and triglycerides. Non-HDL cholesterol is a simple sum: total cholesterol minus HDL. It includes all the cholesterol in particles that can damage the vessel wall, not just LDL.

  2. 2
    The European targets by risk profile

    The ESC/EAS guideline links the target to your risk. Very high risk: LDL below 1.4 mmol/L (55 mg/dL) and non-HDL below 2.2 mmol/L (about 85 mg/dL). High risk: below 1.8 (70) and 2.6 (100). Moderate risk: below 2.6 (100) and 3.4 (130). Low risk: below 3.0 (116) and 3.8 (145). For high and very high risk, a reduction of at least 50% from your baseline is also expected. For moderate and low risk these are values that “may be considered”. The 2025 update left the targets unchanged.

  3. 3
    Who counts as “high risk” is decided by your doctor

    Your doctor estimates that risk with the SCORE2 models (age, sex, blood pressure, smoking and cholesterol). Your category can be very different from that of someone with diabetes or cardiovascular disease. A total cholesterol of 5 mmol/L (about 190 mg/dL) or more is a reason to look for other risk factors. If your LDL is above 4.9 mmol/L (190 mg/dL), ask about familial hypercholesterolaemia, an inherited condition.

  4. 4
    Why non-HDL and apoB are often better than LDL alone

    LDL only measures the cholesterol inside LDL particles. A meta-analysis of epidemiological studies (Sniderman et al., 2011) found that apoB, which reflects the number of harmful particles, predicted risk best (standardised risk ratio 1.43), ahead of non-HDL (1.34) and LDL (1.25). In people on statins, non-HDL predicted risk better than LDL (Boekholdt et al., JAMA 2012). A 2025 systematic review concludes that apoB remains more accurate than LDL and non-HDL when they disagree. That matters most with high triglycerides, overweight and diabetes, where the ESC explicitly recommends non-HDL.

In practice

At your next blood test, look not only at LDL but also at non-HDL (a simple sum) and possibly apoB. Leave the interpretation to your doctor.

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Sources

Evidence: strongRCTs and genetic studies

Cholesterol: is HDL, the “good” cholesterol, really good?

Why HDL is a marker and not a dial to turn.

  1. 1
    A marker, not a goal

    In population studies, low HDL goes together with more cardiovascular disease. But large randomised trials with niacin and CETP inhibitors raised HDL without fewer heart attacks or strokes. Genetic studies (Mendelian randomisation) also show that genes that raise HDL do not lower heart attack risk.

  2. 2
    Values: no target

    The European guideline sets no target for HDL. It uses it to refine your risk estimate. An HDL of around 1.0 mmol/L (about 40 mg/dL) or lower is a signal of higher risk and a reason to look at other risk factors.

  3. 3
    Very high is not better either

    In the Canadian CANHEART study, mortality was raised at both low and very high HDL levels (a U-shaped relationship). At very high levels it was mainly deaths from causes other than heart disease or cancer. In women this only became significant above about 90 mg/dL (2.3 mmol/L).

  4. 4
    And exercise?

    Regular exercise raises HDL and lowers triglycerides. The heart benefit of exercise therefore does not come from HDL alone, and training remains worthwhile. Artificially pushing HDL up with supplements or drugs did not pay off in trials.

In practice

Make sure your HDL is not too low, but focus on LDL or non-HDL, blood pressure, not smoking and enough exercise.

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Sources

Evidence: strongEuropean guideline

Cholesterol with diabetes: stricter targets

Why the limits differ and why non-HDL and apoB count extra.

  1. 1
    Why different?

    People with diabetes have a higher average risk of cardiovascular disease. The guideline therefore sets stricter LDL targets, depending on type, duration and any organ damage.

  2. 2
    Targets in type 2 diabetes

    ESC/EAS 2019: at very high risk, LDL below 1.4 mmol/L (55 mg/dL) and at least a 50% reduction. At high risk, for example diabetes for more than 10 years or with one major extra risk factor, below 1.8 mmol/L (70 mg/dL) and at least a 50% reduction. At moderate risk, type 2 under 50 years without other risk factors, below 2.6 mmol/L (100 mg/dL).

  3. 3
    Type 1 diabetes

    In type 1 diabetes, statins are recommended at high or very high risk. Type 1 under 35 years falls in the moderate category.

  4. 4
    Non-HDL and apoB count extra

    The ESC explicitly recommends non-HDL in diabetes. A study in people with type 2 diabetes and an LDL within target showed that about a quarter still had a non-HDL or apoB that was too high. LDL alone can therefore underestimate the risk.

In practice

If you have diabetes, your doctor determines your risk category and your target. What is “good” for others may be too high for you.

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Sources

Evidence: strong for the riskno proven treatment yet

Cholesterol: Lp(a), the inherited risk factor

What it is, when it is high and what you can do.

  1. 1
    What is it?

    Lp(a) is an LDL-like particle with an extra protein (apo(a)) attached. Its level is more than 90% determined by your genes, stays fairly stable throughout life and barely changes with lifestyle.

  2. 2
    Why measure it?

    A high Lp(a) raises cardiovascular risk independently of your LDL, even when that is well controlled. European guidelines recommend having Lp(a) measured at least once in your life, preferably with your first lipid profile. A 2026 American guideline also recommends universal testing.

  3. 3
    Which values?

    Below 30 mg/dL (75 nmol/L): lower risk. Between 30 and 50 mg/dL (75 to 125 nmol/L): intermediate. Above 50 mg/dL (about 105 to 125 nmol/L, depending on the conversion): higher risk. The relationship is continuous, there is no magic cut-off. Note: mg/dL and nmol/L are not interchangeable, the guideline prefers nmol/L.

  4. 4
    What can you do about it?

    Diet, exercise and weight loss have little or no effect on Lp(a). Neither do statins, ezetimibe and bempedoic acid, and statins may even raise it slightly. PCSK9 inhibitors and inclisiran lower it by about 20 to 30%, but that is secondary to their LDL effect. With a high Lp(a), you tackle the other risk factors more strictly (LDL, blood pressure, smoking), together with your doctor.

  5. 5
    New drugs: no proof yet

    Drugs that specifically lower Lp(a) are being tested. In September 2026 the manufacturer reported that pelacarsen, the first with an outcomes trial, did lower Lp(a) but did not significantly reduce cardiovascular events (8,323 patients with cardiovascular disease, topline results, full data to follow). Other trials are still running. Testing remains recommended, but there is no proven treatment yet.

In practice

Have your Lp(a) measured once and discuss the result with your doctor. If it is high, you compensate with stricter control of everything else, not with supplements.

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Sources

Evidence: strongRCTs and meta-analyses

Cholesterol: how much influence do you have?

What diet and exercise realistically do, and where they fall short.

  1. 1
    What diet realistically does

    Replacing saturated fat with polyunsaturated fat lowers LDL by about 0.05 mmol/L (2 mg/dL) per 1% of your energy. Soluble fibre (3.5 to 7 g a day, for example from oats and legumes) lowers LDL by 0.2 to 0.35 mmol/L. Plant sterols (2 g a day, in fortified products) lower LDL by about 10%, more gives no extra effect and an effect on heart attacks has not been shown.

  2. 2
    Combining works best

    In a randomised trial in 345 people with high cholesterol (Jenkins et al., JAMA 2011), LDL fell by about 13% after 6 months on a “portfolio” diet: nuts, soy protein, soluble fibre and plant sterols. That was more than on a standard low-fat diet. The better people stuck to it, the bigger the drop.

  3. 3
    Exercise and weight

    Exercise and weight loss mainly lower your triglycerides and raise HDL. The effect on LDL is smaller. They remain important for your overall heart risk.

  4. 4
    Where lifestyle is not enough

    At high risk the guideline asks for a reduction of at least 50%. Diet alone usually cannot achieve that, which takes statins, ezetimibe and other drugs, sometimes combined. For inherited causes (familial hypercholesterolaemia, high Lp(a)) diet is not the answer. Supplements without shown LDL-lowering effect and safety are not recommended by the guideline.

In practice

Oats and legumes, nuts, olive oil instead of butter and a bit more exercise can lower your LDL by roughly a tenth to an eighth. If you have high risk or an inherited tendency, your doctor decides whether medication is needed.

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Sources

Evidence: strongCochrane review and meta-analyses

Omega-3: fish, fish oil and what it really does

What omega-3 does for your heart, triglycerides and muscles, and when supplements make sense.

  1. 1
    Heart and blood vessels: little to no effect from supplements

    A Cochrane review of 86 randomised trials (Abdelhamid et al., 2020) concluded, with moderate- to high-quality evidence, that increasing EPA and DHA has little or no effect on mortality or cardiovascular disease. The evidence comes mainly from supplement trials. A later meta-analysis of 40 studies (Bernasconi et al., 2021) did find small, dose-dependent reductions, for example 13% fewer heart attacks (RR 0.87). So the reviews differ in their conclusions, and the effects are small in any case.

  2. 2
    Triglycerides: this does work, but mainly at high doses

    Omega-3 lowers triglycerides almost linearly with the dose, and non-HDL cholesterol too (dose-response meta-analysis of 90 RCTs with 72,598 participants, Wang et al., JAHA 2023). For LDL and HDL the relationship was J-shaped. In a randomised trial in people with moderately raised triglycerides, 3.4 g of EPA+DHA a day lowered them by 27%, while 0.85 g a day had no effect (Skulas-Ray et al., 2011). These are medical doses: with very high triglycerides, a doctor decides.

  3. 3
    High doses: more risk of atrial fibrillation

    A meta-analysis of 7 large trials (81,210 patients, followed for 4.9 years on average, Gencer et al., Circulation 2021) found 25% more atrial fibrillation with fish oil supplements (HR 1.25). The risk was higher above 1 g a day (HR 1.49) than at 1 g or less (HR 1.12). Participants were 65 years old on average with higher cardiovascular risk, so this cannot be applied directly to young athletes. It does show that supplements are not harmless.

  4. 4
    Muscles and training: at most a very small effect

    A meta-analysis in healthy young and older adults (Adv Nutr 2023) found no significant effect of omega-3 on muscle mass (SMD 0.07) or muscle function (SMD 0.03), and a very small effect on muscle strength (SMD 0.12). The certainty of the evidence was moderate and many studies had a high risk of bias. Dose, age and combining it with strength training did not change this.

  5. 5
    Eating fish is the best-supported option

    For eating fish itself, the message is more consistent: about two servings of fatty fish a week, such as salmon, mackerel or herring (ACC overview, 2021: the benefit for fatal cardiovascular events appears from about that level). Over-the-counter fish oil is not routinely recommended for prevention. Plant-based ALA (flaxseed, walnuts) had little or no effect on mortality in the Cochrane review, with a small reduction in cardiovascular events and arrhythmias.

In practice

Eat fish twice a week, preferably fatty fish. A fish oil supplement is not needed for most healthy athletes. If you have high triglycerides or heart disease, your doctor decides on a dose.

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Evidence: strong for blood pressure, moderate for heart diseasemeta-analyses and RCTs

Salt and blood pressure: what really counts?

What less salt does for your blood pressure and heart, the role of potassium and what it means for athletes.

  1. 1
    Blood pressure: less salt lowers it, especially if it is already high

    A dose-response meta-analysis of experimental studies (Filippini et al., Circulation 2021) found a nearly linear relationship between sodium intake and systolic and diastolic blood pressure across the whole range, including in people without high blood pressure. The effect was larger in those who already had higher blood pressure. In the CARDIA-SSBP crossover trial (Gupta et al., JAMA 2023, 213 adults aged 50 to 75), systolic blood pressure after a week on a low-sodium diet was on average 8 mmHg lower than after a week on a high-sodium diet, in about 75% of participants, including those taking blood pressure medication. Each diet lasted only a week, so the study says nothing about the long term.

  2. 2
    Heart and vessels: a clear link, but hard trials are missing

    In a pooled analysis of 6 cohorts with 10,709 adults and repeated 24-hour urine collections (Ma et al., NEJM 2022), 1,000 mg more sodium a day went with 18% more cardiovascular risk, and 1,000 mg more potassium with 18% less. The quarter with the highest sodium excretion had 60% more risk than the quarter with the lowest. The authors attribute the J-shaped relationship seen in older studies, where very low sodium also went with more risk, to how sodium was estimated there. A Cochrane review (Adler et al., 2014) concluded that the trials lacked the power to confirm a clinically important effect on mortality and cardiovascular disease. Advice to cut salt lowered systolic blood pressure by 1.2 mmHg on average in people with normal blood pressure and by 4.1 mmHg in people with high blood pressure.

  3. 3
    Potassium salt substitute: the strongest trial

    The SSaSS trial (Neal et al., NEJM 2021) assigned, by village, 20,995 adults with a previous stroke or poorly controlled high blood pressure (aged 60 or older) to a salt substitute with less sodium and extra potassium or to regular salt. After 4.7 years on average, there was 14% less stroke (RR 0.86), 13% fewer major cardiovascular events (RR 0.87) and 12% fewer deaths (RR 0.88). It was an open-label trial in rural China. The main safety outcome was hyperkalaemia, too much potassium in the blood. If you have kidney disease or take certain medication, discuss such a substitute with your doctor first.

  4. 4
    Athletes: sweating costs sodium, but extra salt is rarely needed

    A 2018 systematic review found minimal evidence that taking sodium during exercise improves endurance performance: only 1 of 5 studies saw a benefit. A 2022 review says replacing sodium is advisable for exercise lasting more than 2 hours, in the heat or with very high sodium losses in sweat (more than 3 to 4 g). The link between sodium and muscle cramps remains uncertain. Outside those cases, the reviews give no reason to take extra sodium.

  5. 5
    How much, and where does it come from?

    The WHO guideline is less than 2,000 mg of sodium a day, about 5 g of salt. In the cohorts of the NEJM analysis, median intake was 3,270 mg of sodium, about 8 g of salt. The Harvard researchers name adding less salt, fewer store-bought processed products and eating out less as ways to cut sodium, and fruit, leafy greens, potatoes, beans, dairy and fish to raise potassium.

In practice

Less salt lowers your blood pressure, especially if it is already high. Aim for under 5 g of salt (2,000 mg of sodium) a day, watch processed products and eating out in particular, and eat more potassium-rich food. Athletes only need extra salt during long exercise, in the heat or with very heavy sweat losses. If you have high blood pressure or kidney disease, or take medication, discuss potassium salt substitutes with your doctor first.

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02

Protein and muscle

How much protein is safe and what it does to your kidneys.

1 topic

Evidence: moderate to strongmeta-analysis and guidelines

Protein and kidneys: does a lot of protein harm your kidneys?

What the research says about high protein intake in healthy people, and when it is different.

  1. 1
    With healthy kidneys: no harm shown

    A meta-analysis of 28 studies with 1,358 participants (Devries et al., J Nutr 2018) compared higher-protein diets (at least 1.5 g per kilo, at least 20% of energy or at least 100 g a day) with normal or lower intake. It found no adverse effect on kidney function (GFR) in healthy adults. After the intervention, GFR was even slightly higher with high intake, but the change in GFR did not differ between groups. In people with obesity, type 2 diabetes or high blood pressure, the authors also saw no sign of harm.

  2. 2
    What sports organisations say

    The International Society of Sports Nutrition position stand (Campbell et al., 2007) states that 1.4 to 2.0 g of protein per kilo per day is safe for people who exercise and may improve training adaptations. In healthy, active people on a varied diet, that intake is not harmful to kidney function or bone metabolism. The recommended dietary allowance (RDA) for adults in general is 0.8 g per kilo. The ISSN considers it inappropriate to extend concerns from research in kidney patients to healthy people with normal kidney function.

  3. 3
    If you already have kidney disease, it is different

    In chronic kidney disease (CKD) stages 3 to 5 without dialysis, the 2024 KDIGO guideline suggests 0.8 g of protein per kilo per day and not going above 1.3 g per kilo when there is a risk of progression. The 2020 KDOQI guideline is stricter and advises 0.55 to 0.6 g per kilo in stable CKD stages 3 to 5 without diabetes. So the guidelines differ, and people on dialysis often need more protein. If you have kidney disease, discuss protein with your nephrologist or a dietitian, not with an online calculator.

In practice

With healthy kidneys, a protein intake within the usual sports range is not harmful to your kidney function according to the research. If you have kidney disease, or suspect you might, have your kidney function checked first and follow the advice of your doctor or a dietitian.

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03

Weight and eating patterns

Keto, intermittent fasting, ultra-processed food and sugar: what they really deliver.

5 topics

Evidence: moderatemeta-analysis of RCTs

Ketones and keto: the sober version

What ketosis is, whether it beats other diets and what happens to your LDL.

  1. 1
    What is ketosis?

    On very few carbohydrates (in the studies, at most 50 g a day), your liver turns fat into ketones, an alternative fuel. This is normal in healthy people and different from ketoacidosis, a dangerous derailment that mainly occurs in diabetes.

  2. 2
    Slightly more weight loss, no miracle

    A meta-analysis of 13 randomised trials (Bueno et al., 2013, 1,415 participants) found about 0.9 kg more weight loss after at least a year on keto than on a low-fat diet. That difference is statistically significant, but small.

  3. 3
    Your blood fats change

    Triglycerides and diastolic blood pressure fell more and HDL rose, but LDL also rose more than on a low-fat diet. If you try keto, it is wise to have your blood values followed up.

In practice

Keto can work for people who stick with it long term, but it is not a miracle route.

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Sources

Evidence: strongCochrane review and RCTs

Intermittent fasting: does it really work?

What fasting does for weight and muscle, and who it is not suitable for.

  1. 1
    What is it?

    Intermittent fasting is an umbrella term: time-restricted eating (for example only eating within an 8-hour window), alternate-day fasting or periodic fasting, such as the 5:2 schedule. In research these variants are often looked at together.

  2. 2
    Weight: no clear advantage over simply eating less

    A Cochrane review from February 2026 (Garegnani et al.) pooled 22 randomised trials with 1,995 adults with overweight or obesity, mostly followed for up to 12 months. Intermittent fasting made little to no difference to weight loss and quality of life compared with standard dietary advice, and the difference compared with doing nothing was also small. The certainty of the evidence is limited: many studies are small and short, and long-term data are missing.

  3. 3
    When you eat matters little at equal calories

    In a 12-month RCT in 139 people with obesity (Liu et al., NEJM 2022), both groups followed the same calorie-restricted diet, but one group only ate between 8:00 and 16:00. After a year, mean weight loss was 8.0 kg versus 6.3 kg, a difference that was not statistically significant (P = 0.11). Time-restricted eating was therefore not more effective than simply restricting calories.

  4. 4
    And your muscles?

    A meta-analysis of 15 trials with 338 participants (2025) found that time-restricted eating combined with exercise can reduce fat mass, with no significant effect on fat-free mass (p = 0.07, borderline). An 8-week RCT in people with overweight (Kotarsky et al., 2021) showed more fat loss in the fasting group (9.0% versus 3.3%), while fat-free mass rose in both groups. The studies are small and short, so this is a cautious conclusion.

  5. 5
    Not for everyone

    This is general medical caution, not a study result. Talk to your doctor first, or skip fasting, if you are pregnant or breastfeeding, have a history of eating disorders, have diabetes treated with insulin or medication that can cause low blood sugar, or are under 18.

In practice

Intermittent fasting can work if it is simply an easy way for you to eat less. It is not magic: what counts is your total calories, enough protein and regular training.

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Sources

Evidence: moderateumbrella review (observational) and two small RCTs

Ultra-processed food: is it really that bad?

What NOVA means, what the big review says and what two feeding experiments show.

  1. 1
    What counts as “ultra-processed”?

    Most studies use the NOVA system, which sorts food by degree of industrial processing into four groups: unprocessed or minimally processed, processed culinary ingredients, processed food and ultra-processed food. Examples in the studies include sugary breakfast cereals, ready meals, soft drinks, breakfast bars and a ready-made lasagne. The category is broad. The first author of the UPDATE trial notes that not every ultra-processed product is unhealthy based on its nutritional profile.

  2. 2
    Observational research: a consistent link, low-quality evidence

    An umbrella review of 45 meta-analyses with about 9.9 million participants (Lane et al., BMJ 2024) found a link between more ultra-processed food and higher risk for 32 of 45 outcomes (71%), including mortality, cancer and cardiovascular, metabolic and mental health outcomes. According to the lead author, the strongest analyses showed about 50% higher risk of cardiovascular death and of common mental disorders. The quality of the evidence was low, though: by GRADE, 22 analyses were low quality, 19 very low and only 4 moderate. There were also no pooled analyses of randomised trials. So these are associations, not proven cause.

  3. 3
    Experiments: you eat more of it

    In an inpatient RCT in 20 adults (Hall et al., Cell Metabolism 2019), participants ate an ultra-processed diet for two weeks and an unprocessed diet for two weeks, as much as they liked. The diets were matched for energy density, macronutrients, sugar, sodium and fibre, among other things. On the ultra-processed diet they ate 508 kcal a day more on average and gained 0.9 kg, versus losing 0.9 kg on the unprocessed diet. In the UPDATE trial (Dicken et al., Nature Medicine 2025), 55 adults with overweight ate a minimally processed or an ultra-processed diet following the UK Eatwell guidance for 8 weeks each, in random order. Both led to weight loss, but the minimally processed diet more (−2.06% versus −1.05%, P = 0.024), through less fat mass and body water, with no change in fat-free mass. Both studies are small and short: they mainly show that the effect exists, not how large it is in the long run.

  4. 4
    What do you do with this?

    The UPDATE trial shows that even ultra-processed food that meets dietary guidelines can lead to weight loss, just less than minimally processed food. So the research does not say you must cut everything that is ultra-processed. It does suggest that more minimally processed food in your day helps with weight loss. Participants also reported better control of cravings, especially for savoury food, on the minimally processed diet.

In practice

The link between lots of ultra-processed food and poorer health is consistent, but it comes mainly from low-quality observational research, and the two feeding experiments are small and short. Build your diet mainly around unprocessed and minimally processed products and limit ready meals, breakfast bars, soft drinks and snacks, without overdramatising it.

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Evidence: moderatemeta-analyses of RCTs and cohort studies, guideline

Sugar: how much is too much?

What the research says about weight and health, the WHO limit and where to start.

  1. 1
    Weight: sugar works mainly through calories

    A meta-analysis of 30 trials and 38 cohort studies (Te Morenga et al., BMJ 2013) found that adults who ate less sugar lost 0.8 kg on average, and those who ate more gained 0.75 kg, in trials where they could eat freely. When sugar was swapped for other carbohydrates with the same calories, weight did not change (0.04 kg). So the effect comes from energy intake, not from a special property of sugar. In trials in children, adherence to the advice was low and no change was seen.

  2. 2
    Health: mainly sweet drinks, and mostly weak evidence

    An umbrella review of 73 meta-analyses covering 83 health outcomes (Huang et al., BMJ 2023) found harmful associations between sugar intake and 18 endocrine or metabolic outcomes, 10 cardiovascular and 7 cancer outcomes, plus 10 others. Most of the evidence was observational and of low quality. Moderate quality existed only for sugar-sweetened drinks and weight, and for added sugar and fat accumulation in liver and muscle. The authors recommend keeping free or added sugar under 25 g a day and limiting sugar-sweetened drinks to less than one serving a week. That matches the stricter, conditional WHO limit of 5% of your energy.

  3. 3
    The WHO limit: under 10% of your energy

    The WHO (2015) recommends keeping free sugars under 10% of total energy (strong recommendation) and, if possible, under 5%, about 25 g a day (conditional recommendation, mainly based on tooth decay). Free sugars are sugars added to food or drinks, plus those in honey, syrups and fruit juice, not those in whole vegetables and fruit or in milk. At 2,700 kcal, 10% is about 68 g. A can of sugar-sweetened soda contains up to 40 g. In Europe, adult intake ranges from about 7 to 8% of energy to 16 to 17% in countries like Spain and the United Kingdom.

  4. 4
    What this does and does not say

    These limits concern the sugars in your everyday diet, not carbohydrates as fuel during long or hard exercise. That is a separate topic. The reviews mostly show associations, and for weight the effect comes from the extra energy. Drinks stand out: the strongest evidence on weight concerns sugar-sweetened drinks.

In practice

Sugar works mainly through extra calories. Keep free sugars under 10% of your energy (at 2,700 kcal about 68 g), aiming lower, and watch soft drinks, fruit juice and other sweet drinks in particular. This is about your everyday diet, not carbohydrates during long exercise.

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Evidence: moderatemeta-analyses of cohort studies and a Cochrane review of RCTs

Fibre and whole grains: what do they really deliver?

What the research says about heart, diabetes and mortality, the role of whole grains and how much fibre to eat.

  1. 1
    More fibre goes with less disease and death

    A series of systematic reviews in The Lancet (Reynolds et al., 2019) pooled 185 prospective studies, nearly 135 million person-years, and 58 clinical trials with 4,635 adults. Compared with the lowest consumers, the highest fibre consumers had 15 to 30% lower all-cause and cardiovascular mortality, and less coronary heart disease, stroke, type 2 diabetes and colorectal cancer. In the trials, people on more fibre had lower body weight, lower systolic blood pressure and lower total cholesterol. The benefit was greatest at 25 to 29 g of fibre a day. The certainty of the evidence was rated moderate.

  2. 2
    Whole grains instead of refined grains

    A dose-response meta-analysis of 45 prospective studies (Aune et al., BMJ 2016) found, per 90 g of whole grains a day, meaning three servings of 30 g, about 19% less coronary heart disease, 22% less cardiovascular disease and 17% lower all-cause mortality. Mortality from stroke (14%), cancer (15%), respiratory disease (22%), infections (26%) and diabetes (51%) was also lower. The link was seen for whole grain bread, whole grain breakfast cereals and added bran. For refined grains, white rice or grains in general, there was little evidence of a link. In the Lancet series, the certainty of the evidence for whole grains was low to moderate. These are observational associations, not proof of cause.

  3. 3
    Randomised trials: less clear

    A Cochrane review (Kelly et al., 2017) looked for randomised trials of at least 12 weeks. It found nine with 1,414 participants and concluded that there is insufficient evidence of an effect of whole grain diets on cardiovascular outcomes or on risk factors such as blood fats and blood pressure. No study reported heart attacks, strokes or deaths. The review calls for larger and longer trials. In the trials of the Lancet series, whole grains did go with lower body weight.

  4. 4
    How much fibre, and where do you stand?

    EFSA (2010) considers 25 g of fibre a day adequate for normal bowel function in adults, and sees extra health benefits at higher intakes. In the 2022-2023 Belgian national food consumption survey, mean intake was 16 g a day (17 g in Flanders), so on average well below that 25 g. Most fibre comes from cereal products, vegetables and fruit. The Lancet authors suggest building meals and snacks around whole grains, vegetables, pulses and fresh fruit.

In practice

Aim for at least 25 g of fibre a day and choose whole grains, vegetables, pulses and fruit more often instead of white grains. The strongest links come from observational research, and randomised trials have not yet been able to confirm the effect of whole grains on their own.

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04

Lifestyle and recovery

Habits that affect your health, sleep and training.

3 topics

Evidence: moderate to strongmeta-analyses and a small RCT

Alcohol: what does it do to your health and your training?

What the research says about risk, muscle recovery and sleep, even when you drink little.

  1. 1
    No protection, and risk rises with the amount

    Older studies suggested that a glass a day protects, but they often compared drinkers with people who had quit, frequently for health reasons. That distorts the picture. A meta-analysis of 107 cohort studies with 4.8 million participants (Zhao et al., 2023) found, after correcting for this, no significant protection at low intake (under 25 g of alcohol a day) compared with people who never drank. Mortality risk did rise from 25 g a day in women and from 45 g a day in men. A standard drink contains 10 g of alcohol in Belgium.

  2. 2
    Where is the limit? Around 100 grams a week

    An individual-participant analysis of 599,912 drinkers in 83 studies (Wood et al., Lancet 2018) found the lowest mortality risk at or below about 100 g of alcohol a week, roughly ten standard drinks. For cardiovascular diseases other than heart attack, there was no threshold below which drinking less stopped being linked to lower risk. Only for heart attack was more alcohol linked to lower risk. The authors conclude that the limits in most guidelines are too high. These are observational studies: they show an association, not a cause.

  3. 3
    Muscle recovery: heavy drinking after training blunts muscle building

    In a randomised cross-over trial in 8 active men (Parr et al., PLoS One 2014), participants drank 1.5 g of alcohol per kilo of body weight after hard training, about 12 standard drinks. Muscle protein synthesis was lower than with protein alone, even when 25 g of protein was taken with it. Note: this is a high dose in a small study. Less is known about moderate amounts, so the evidence mainly concerns heavy drinking sessions after training.

  4. 4
    Sleep: you fall asleep faster, but the night is worse

    A meta-analysis of 27 studies in healthy adults (Gardiner et al., Sleep Medicine Reviews 2025) found that REM sleep is disrupted even after a low dose (up to 0.5 g per kilo of body weight, about two standard drinks according to the authors), and that this gets worse the more you drink. High doses may shorten the time to fall asleep but worsen the REM disruption. For total sleep time and sleep efficiency, the uncertainty was too large to conclude anything. Sleep is part of recovery, so this matters for your training too.

In practice

The research points to about 100 g a week (roughly ten standard drinks) as an upper limit, and less is better. Avoid drinking heavily after training and right before bed. If you have a medical condition or take medication, discuss alcohol with your doctor.

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Evidence: moderate to strongumbrella review and position stand

Caffeine: what does it do for your training?

What the research says about performance, dose, timing and the price you pay in sleep.

  1. 1
    It works for strength and endurance

    An umbrella review of 11 reviews with 21 meta-analyses (Grgic et al., BJSM 2020), all of moderate or high quality, found that caffeine improves performance in aerobic endurance, muscle strength, muscular endurance, power, jumping and speed. Not every analysis showed a clear direction once the prediction interval is taken into account, and most studies were in young men. The effect is real, but it differs per person and per type of effort.

  2. 2
    Dose and timing: 3 to 6 mg per kilo, an hour before

    According to the International Society of Sports Nutrition position stand (2021), caffeine consistently improves performance at 3 to 6 mg per kilo of body weight, and the lowest effective dose may be around 2 mg per kilo. Very high doses (9 mg per kilo or more) often cause side effects without extra benefit. It is most often taken about 60 minutes before training, although the ideal timing depends on the source. Your response, including on sleep and anxiety, differs per person, partly because of genetic differences in how you metabolise caffeine.

  3. 3
    Safe limits according to EFSA

    The European Food Safety Authority (EFSA, 2015) sees no safety concern for single doses up to 200 mg (about 3 mg per kilo for a 70 kg adult), even shortly before intense exercise, or for daily intakes up to 400 mg in adults who are not pregnant. For pregnant and breastfeeding women the limit is 200 mg a day. Note: the top of the sports range (6 mg per kilo) is above that 200 mg per dose for most people. So start low and only build up if you tolerate it well.

  4. 4
    Sleep: the price of caffeine late in the day

    A meta-analysis of 24 studies (Gardiner et al., Sleep Medicine Reviews 2023) found that caffeine shortened total sleep time by 45 minutes on average and sleep efficiency by 7%. Falling asleep took 9 minutes longer, time awake after sleep onset 12 minutes longer, and deep sleep fell by about 11 minutes. To avoid losing sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 hours before bedtime and a standard pre-workout (217.5 mg) at least 13.2 hours before. If you train in the evening, that is a real trade-off.

In practice

If you use caffeine, start around 3 mg per kilo, about an hour before training, and see how you respond. Do not take it late in the day: allow at least nine hours before bed, and more than thirteen for a pre-workout. Very high doses (9 mg per kilo or more) give no extra benefit, only side effects.

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Evidence: moderateumbrella review, meta-analyses and one RCT

Coffee: good for your health or not?

What the research says about mortality, heart rhythm, cholesterol and how much is safe.

  1. 1
    No sign of harm at usual amounts

    An umbrella review of 201 meta-analyses of observational studies and 17 meta-analyses of interventional studies (Poole et al., BMJ 2017) found that coffee was more often linked to benefit than to harm. The largest benefit was at 3 to 4 cups a day versus none: about 17% lower all-cause mortality, 19% lower cardiovascular mortality and 15% lower cardiovascular disease. These are observational associations, not proof of cause. The exceptions were pregnancy and women at high risk of fractures. The studies looked at coffee itself, not at sugar, syrup or cream.

  2. 2
    Heart rhythm: no need to cut out coffee

    In the DECAF trial (Wong et al., JAMA 2025), 200 patients with persistent atrial fibrillation after a successful cardioversion were randomised to about one cup of regular coffee a day on average or to complete abstinence from coffee and caffeine. After 6 months the rhythm problem had returned in 47% of the coffee group versus 64% of the abstinence group (HR 0.61). The trial was open-label and ran for only 6 months, and just 69% of the abstinence group stuck to the ban throughout. So it does not support the old advice to cut coffee by default, but it is a single study in patients.

  3. 3
    Cholesterol: choose filtered coffee

    Unfiltered coffee, such as French press, boiled coffee and Turkish or Greek coffee, contains cafestol and kahweol, substances that raise LDL cholesterol. A meta-analysis of 14 randomised trials (Jee et al., 2001) found a dose-dependent rise in total and LDL cholesterol with unfiltered coffee, and very little with filtered coffee. A later meta-analysis of RCTs (Cai et al., 2012) confirmed that coffee, especially unfiltered, raises total cholesterol, LDL and triglycerides, and that people with high blood fats are more sensitive.

  4. 4
    How much is safe? Up to 400 mg a day

    EFSA (2015) considers a habitual intake of up to 400 mg of caffeine a day from all sources of no concern for adults who are not pregnant, and 200 mg a day for pregnant women. A cup of coffee contains roughly 80 to 110 mg, so 400 mg comes down to four or five cups. Caffeine from energy drinks and pre-workouts counts too. A single dose of 100 mg can delay falling asleep and shorten sleep in some adults.

In practice

Up to about 400 mg of caffeine a day (four to five cups) is considered safe by EFSA for healthy adults, and 3 to 4 cups of coffee go together with lower risk in observational research. Choose filtered coffee if your LDL is high and keep sugar and cream limited. If you are pregnant, stay at 200 mg a day. If you have a heart rhythm disorder, discuss coffee with your doctor.

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