Lunch break, canteen. At the next table there's a salad with cucumber, tomato and three strips of chicken breast. A textbook plate for anyone trying to lose weight. Now imagine the person behind it runs twelve kilometres in the evening, does squats afterwards and wonders on Thursday why everything feels like wading through mud. The plate looks exemplary. It's just built for a different job.
This article is for everyone who trains a lot and still feels flat despite eating “healthy”. And for everyone who wants to lose weight and needs to know why “just keep eating little while training a lot” backfires. I'm a personal trainer, nutrition coach and trained chef. The chef's craft is the common thread here, because the solution is less about counting calories and more about kitchen technique.
Why you eat too little when you train a lot, without noticing
The obvious assumption goes like this: my body burns energy, so it will ask for more, and I'll eat more. In the short term, that isn't true. A meta-analysis by Schubert and colleagues covering 29 studies (2013) found that energy intake barely changes after acute exercise. You don't eat more afterwards, but you have burned more. The difference is a gap that grows quietly.
The hormones fit the picture. The hunger hormone ghrelin drops by a median of 16.5 % after a session, while the satiety hormone PYY rises slightly (Schubert et al., 2014). The dampening is strongest after intense sessions (McCarthy et al., 2024). Researchers call this exercise-induced appetite suppression. It isn't an eating disorder, it's a body that wants some peace and quiet after hard work.
The honest caveat: these data come from short lab studies with small groups, mostly young men, and publication bias has been documented. The true effects may well be smaller. How much individual people make up for it over weeks varies a lot and is poorly studied. Only one thing is certain: “your body will take what it needs” doesn't hold up at high training volumes.
What “too little” actually means: energy availability
The technical term is energy availability: what's left for your immune system, hormones, repair and mood after training? The basics are in the article on eating for two sessions a day. The 2023 IOC consensus statement describes how low energy availability in sport often develops unintentionally, because demand grows faster than appetite and everyday life can keep up. It affects women and men. Nobody knows how common it is among recreational athletes between 30 and 50, because there are no reliable numbers.
How you notice it before the scales do: your standard sessions feel heavier, your week falls apart from Thursday onwards, you're more irritable. These are observations from coaching, not a test. My order for troubleshooting: first the plate, then sleep, the training plan last. Then add more energy around your sessions for one to two weeks and see whether anything changes.
And there's a line I want to draw clearly, once. If your period stops, you've been constantly tired for weeks, you keep catching infections, you've had stress fractures, or your thoughts revolve almost entirely around food, that belongs in the hands of a doctor or psychotherapist. The term RED-S describes the clinical picture. Alethics doesn't diagnose.
The chef's solution: raise energy density, not the size of the plate
Over the course of a day, people eat a surprisingly constant amount of food by volume. How much energy comes in depends mainly on energy density, meaning calories per gram. When losing weight, you use this to feel full while staying in a deficit. When you train a lot, you flip the lever: same volume, more inside. Like a stock you reduce until it's richer.
| Food (rounded) | Energy |
|---|---|
| Cooked rice, 100 g | about 130 kcal |
| Leafy salad, 100 g | about 15 kcal |
| Oil, 1 tablespoon | about 90 kcal |
| Nut butter, 1 tablespoon | about 90 to 100 kcal |
| Honey, 1 tablespoon | about 60 kcal |
| Nuts, 100 g | about 550 to 650 kcal |
Five moves that follow from this: use fat as a tool (finish dishes with oil or butter), swap the base (rice and potatoes as the foundation, vegetables on the side), use sweet density (honey, banana in your porridge), sprinkle nuts and cheese, and take your sauce seriously, because it can add 150 to 300 calories to a plate without making it any bigger. I used to be a chef, and a sauce was never an afterthought.
For context: the mechanism is well established, just in the weight-loss direction (Robinson et al., 2022; Hall et al., 2019). In clinical nutrition, enriching normal food is an established craft (ESPEN guideline, for older adults). For people who train a lot, it's a practical conclusion, not an intervention study. Increase step by step, keep the vegetables, and start with the meals furthest away from your next session.
When drinking beats chewing: liquid calories and snacks in between
“Liquid calories are bad” is true in its original context. In a classic study (DiMeglio & Mattes, 2000), 15 adults received about 450 extra calories a day for four weeks each, once as soda and once as solid sweets. The solid extra was almost entirely compensated for in the rest of their diet, the liquid one wasn't, and body weight only rose during the liquid phase. A small sample, but the direction is consistent.
When you're losing weight, that's a leak. When you train a lot and your appetite is tired, it's a tool: the energy gets in without your satiety system blocking the next meal. My go-to: 300 ml whole milk, a banana, 50 g oats, a tablespoon of nut butter and a tablespoon of honey, about 630 calories together. Add three main meals and two to three planned in-between stops, so nobody has to shovel down 1,500 calories in the evening. Important: liquid is the bridge, not the foundation.
Protein stays the same, but not at the expense of energy
Your protein needs barely change at high volumes: 1.2 to 2.0 g per kilo per day (ACSM, 2016). My anchor is around 1.6, spread over three to five portions. A single study with six men, industry-funded, points towards the upper end for endurance athletes. It doesn't change any recommendation.
The trap is satiety. If your daily needs are well above 3,000 calories and you flood your plate with lean meat and broccoli, you're full before you've had enough energy. That's a conclusion from the well-documented satiating effect of protein, not a study on athletes. My answer: pair instead of pile (skyr with honey instead of plain low-fat quark, salmon instead of only turkey) and flip the order: base and sauce first, then the protein, palm-sized.
Carbohydrates: the weekly maths in real food
The daily ranges in the ACSM guideline run from 3 to 12 g per kilo, depending on volume. A running week of 60 to 80 kilometres plus strength training mostly lands somewhere between 5 and 10 g/kg on training days, lower on rest days. That's my translation, not a guideline.
Worked example with 70 kilos and 6 g/kg: 420 grams of carbohydrates. That's roughly 150 g of oats, half a kilo of cooked rice, three bananas, two slices of bread with honey, plus juice or milk. That's a lot of food. If you eat low carb out of habit, you structurally won't meet your needs on days like that. If the second half of your week regularly feels sluggish, I look at the carbohydrates in the first half first.
Quick athlete's kitchen: three plates in under 20 minutes
Time is the bottleneck, not knowledge. That's why there are no rigid recipes here, just three building principles (amounts for about 75 kg on a hard day, rounded). The bowl: pre-cooked rice, egg, vegetables from the freezer or pantry, a sauce with some fat, about 900 to 1,100 calories in 15 minutes. The one-pot: cook pasta directly in the sauce, the protein goes in too. And cold-or-warm: oats with whole milk, nut butter, honey and banana.
The technique behind it is mise en place on a small scale: set everything out beforehand, cook rice and potatoes in double batches, add the oil at the end. And the most common mistake: confusing quick with small. There are no studies on recipes as a performance intervention. Cooking for yourself is associated with better diet quality (Mills et al., 2017), but that's correlation, not causation.
Heat and travel
Heat dampens energy intake even further. A meta-analysis of 13 studies with 199 adults found a small effect (Millet et al., 2021); in the subgroup on training in the heat, only four studies, it wasn't statistically confirmed. The data are thin. But the energy needs of a training day don't drop because it's warm. The practical side is experience: cold, liquid, energy-dense, the big plates in the cooler windows of the day, extra calories around midday. On the road, rice, eggs, bananas, nuts, yoghurt or milk and white bread with honey will do, plus two fixed anchors: your breakfast and the bridge after training. When you travel, it's your habits that break, not the plan.
The seven-day check without an app
There is no validated self-test. What works is looking at trends instead of daily values, because both sides of the equation are estimates: self-reported intake is systematically too low (in large surveys, just over a quarter of reports weren't plausible: 27.4 %, Speakman et al., 2025, corrected version), and wearables are off by 27 to 93 % on energy expenditure (Shcherbina et al., 2017). My check is six questions, once a week: Standard sessions feeling heavier? Second half of the week sluggish? Average weight dropping without you wanting it to? Sleeping worse? Irritable, food constantly on your mind? Ravenous in the morning? There's no score. If several answers have been yes for more than a week, food gets adjusted first, and after one to two weeks you take another look. If the check stays off even though you think you're eating enough, two honest tracking days as a sample will help.
My fuel day: an honest case study
Because all of this is only credible if I apply it to myself: I'm up by six at the latest, then meditation, mobility, martial arts, four to five hours of coaching, strength training and a run, usually ten to fifteen kilometres. Around 80 running kilometres a week in total. Running costs roughly 1 calorie per kilo of body weight per kilometre (Margaria et al., 1963). At 75 kilos and 15 kilometres, that's about 1,100 extra calories, a worked example and not my body weight.
And despite eating, by my own estimate I'm short 500 to 1,000 calories a day. That number isn't a measurement, a recommendation or something to copy, it's the problem I'm dealing with right now. What carries over is the method: plan backwards from your sessions, an anchor before, a liquid bridge after, a big meal in the evening, and check trends. The amounts don't carry over. If you train three times a week, you don't need extra food like someone running 80 kilometres.
Bottom line
Your appetite is not a speedometer. Beyond a certain weekly volume, eating is part of training, and the solution isn't willpower or a calorie app, it's craft: raise energy density, build liquid bridges, slot protein in properly, translate carbohydrates into real food and ask yourself six questions once a week. If you want to lose weight, you use the same tools the other way round. The energy density toolkit, three recipe cards, the carbohydrate table and the fill-in check are free in the Fuel Guide (in German): comment FUEL under one of my reels on Instagram.
Medical note: this article doesn't replace medical advice. The kitchen, travel and heat tips and the seven-day check are chef's craft and coaching practice, not study results. The figure of 500 to 1,000 calories is a personal estimate.
Keep reading
- Nutrition for strength and endurance: carbohydrates, protein and timing
- Zone 2 training: heart rate, the talk test and the right weekly dose
- Strength training for runners: which kind works
Sources
- Schubert M. M., Desbrow B., Sabapathy S., Leveritt M. (2013). Acute exercise and subsequent energy intake. A meta-analysis. Appetite 63:92–104. PMID 23274127
- Schubert M. M., Sabapathy S., Leveritt M., Desbrow B. (2014). Acute exercise and hormones related to appetite regulation: a meta-analysis. Sports Med 44(3):387–403. https://doi.org/10.1007/s40279-013-0120-3
- McCarthy S. F., Tucker J. A. L., Hazell T. J. (2024). Exercise-induced appetite suppression: An update on potential mechanisms. Physiol Rep 12(16):e70022. PMID 39187396
- Mountjoy M. et al. (2023). IOC consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 57:1073–1098. PMID 37752011
- Robinson E. et al. (2022). Meta-analysis on energy density. Int J Behav Nutr Phys Act
- Hall K. D. et al. (2019). Ultra-processed diets cause excess calorie intake and weight gain. Cell Metab 30(1):67–77
- Volkert D. et al. (2022). ESPEN guideline on clinical nutrition and hydration in geriatrics. Clin Nutr 41(4):958–989
- DiMeglio D. P., Mattes R. D. (2000). Liquid versus solid carbohydrate. Int J Obes Relat Metab Disord 24(6):794–800. PMID 10878689
- Thomas D. T., Erdman K. A., Burke L. M. (2016). ACSM Joint Position Statement: Nutrition and Athletic Performance. Med Sci Sports Exerc 48(3):543–568. PMID 26891166
- Kato H., Suzuki K., Bannai M., Moore D. R. (2016). PLoS One 11(6):e0157406. https://doi.org/10.1371/journal.pone.0157406
- Mills S. et al. (2017). Int J Behav Nutr Phys Act 14:109. https://doi.org/10.1186/s12966-017-0567-y
- Millet J. et al. (2021). Nutrients 13(10):3424. PMID 34684424
- Speakman J. R. et al. (2025). Nature Food (self-reported energy intake)
- Shcherbina A. et al. (2017). J Pers Med 7(2):3
- Margaria R., Cerretelli P., Aghemo P., Sassi G. (1963). J Appl Physiol 18:367–370. PMID 13932993
- Food values: USDA FoodData Central (rounded standard values)
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