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Eating to build muscle: the surplus, protein and rate of gain

An evidence-based guide to the nutrition half of building muscle. The training side (progressive overload, effort and recovery) is covered in build-muscle basics. This is about what to put on the plate: how big a calorie surplus you actually need, how fast you can realistically expect to gain, how much protein does the job, and why a patient "lean" surplus beats a "dirty bulk." Practical, honest, and grounded in published sports-nutrition consensus.

Here's the whole nutrition side in two sentences: to build muscle, eat a modest energy surplus (roughly 10–20% over maintenance), get enough protein (around 1.6–2.2 g per kg of body weight a day), and aim to gain slowly, about 0.25–0.5% of your body weight per week.[1] That's far slower than most people hope, and it's deliberate: eating a bigger surplus speeds up fat gain rather than muscle gain.[2] Everything below is the detail behind those two sentences, and an honest reset of expectations about how slow "slow" really is.

On this page

  1. Why building muscle needs a surplus
  2. How big should the surplus be?
  3. The realistic rate of gain
  4. A worked rate-of-gain table
  5. Protein: how much, and how to spread it
  6. Lean bulk vs dirty bulk
  7. When appetite is the limit
  8. Building off-season, holding in-season
  9. Honest expectations: muscle is slow
  10. Common questions
  11. Takeaways
  12. References

A framing note before the numbers. Nutrition for muscle gain is well studied, but people differ enormously: training age, sex, genetics, sleep, starting body fat, hormones and health status all shift how much muscle anyone builds and how much of a surplus turns into fat. So this is written as can, tends to and around, never as a guarantee, and every specific figure is a population-level guide drawn from published research rather than a personal prescription. It's general education rather than medical or dietary advice, and it isn't a personalised plan.

Why building muscle needs a surplus

Muscle is tissue, and building new tissue costs energy and raw material. Training provides the signal to grow (that's the whole story of the build-muscle basics guide), but the body builds most readily when it has a little energy to spare: a positive energy balance, where you're taking in slightly more than you burn. Going the other way is measurably unhelpful: a review of this question summarises two separate studies: in the first, resting muscle protein synthesis fell by about 16% in young healthy volunteers after ten days at roughly 80% of energy requirements; in the second, it fell by around 30% in young resistance-trained volunteers after just five days of energy restriction.[3] Eating enough also protects the protein you eat: the joint position statement of the Academy of Nutrition and Dietetics and Dietitians of Canada with the American College of Sports Medicine (United States and Canada) puts it as consuming enough energy so that amino acids are spared for protein synthesis rather than oxidised for fuel.[4]

This doesn't mean a deficit makes muscle gain impossible. The same review concludes that muscle growth is possible in an energy deficit, but proposes it's more likely among people who are new to resistance training, overweight or obese, what's popularly called a "recomposition."[3] For most people who've trained for a while, a small surplus is the standard advice, though it's worth saying plainly that the same review finds the specific surplus needed to maximise muscle gain has never been established.[3] The key word is small: past a modest amount, extra calories don't appear to buy extra muscle, and surplus energy beyond what growth can use has only one place to go.[2]

Common misconception → correct it. "To get big you have to eat big: pile on the calories and let the training sort it out." The first half is half-true: you do need to eat enough. The second half is where people go wrong. In a controlled trial, lifters on a 15% surplus added the most to their skinfolds with no evidence of a group difference in muscle thickness against a 5% surplus or eating at maintenance: the authors concluded that faster rates of body-mass gain primarily increase rates of fat gain rather than augmenting one-rep max or muscle thickness.[2] Eating far more doesn't grow muscle faster. It just grows your waistline and gives you more fat to diet off later.

How big should the surplus be?

The evidence-based answer is: smaller than most people think. A widely cited narrative review of off-season nutrition for bodybuilders recommends a hyper-energetic diet of roughly 10–20% above maintenance energy for gaining muscle without piling on unnecessary fat.[1] In everyday terms, if your maintenance sits somewhere around 2,000–2,500 kcal, that's very roughly an extra 200–500 kcal a day: enough to support growth without spilling over into fat. A separate review of the same question lands in a similar place, advising practitioners to take a conservative approach of about 1,500–2,000 kJ a day (roughly 360–480 kcal) to minimise fat-mass gains.[3]

And the more trained (or leaner) you are, the smaller that surplus should be. The off-season review notes that for highly trained athletes a surplus nearer 200–300 kcal per day may be more appropriate than 500 kcal, specifically to minimise the risk of unnecessary increases in body fat.[1] That's the recurring theme of muscle-gain nutrition: the surplus should stay a gentle nudge rather than a feast.

One honest caveat about all calorie numbers: maintenance is only ever an estimate. Any calculator or app gives you a starting figure. It isn't a fact, and your true maintenance shifts with activity, non-exercise movement and even how much you've been eating. So don't treat "+300 kcal" as precise. The reliable feedback loop isn't the calorie count. It's your rate of weight gain over a few weeks, which is exactly what the next section is about.

Strathlon daily targets view for a muscle-gain goal, showing a modest calorie surplus target alongside a daily protein target
Strathlon's daily targets for a muscle-gain goal: a modest surplus set against maintenance, with a protein target alongside, the two dials that matter most for building muscle.
Common misconception → correct it. "There must be a magic calorie number that builds muscle." There isn't, because your maintenance is a moving estimate, no fixed surplus is "correct" for long. Set a sensible starting surplus (around 10–20%)[1], then adjust by outcome: if the scale is climbing faster than roughly half a percent of your body weight a week, ease off. If it's flat for a few weeks, nudge food up. The number that works is the one that produces the right rate of gain.

The realistic rate of gain

This is the part that resets expectations. Because muscle is built slowly, the goal isn't to gain weight fast. It's to gain it at a pace where most of what you add is muscle rather than fat. The off-season review recommends a target of about 0.25–0.5% of body weight per week for novice-to-intermediate lifters, and says advanced bodybuilders should be more conservative with both the calorie surplus and the weekly weight gain, without putting a specific figure on how much more conservative. It also notes that rates of muscle growth may slow as an individual becomes more advanced, which is why beginners can gain faster and everyone slows down over time.[1]

Put that in real numbers and it feels almost frustratingly gentle. For an 80 kg lifter, 0.25–0.5% a week is roughly 0.2–0.4 kg (about the weight of an apple or two) per week. Over a month that's on the order of one to two kilograms of total weight gain, and only a fraction of that is new muscle. If the scale is shooting up much faster than that, the surplus is almost certainly too big and the extra is fat.

Why so slow? Because eating more doesn't seem to raise the rate of muscle growth itself. In an eight-week supervised trial, 17 resistance-trained lifters were assigned to eat at maintenance, at a 5% surplus or at a 15% surplus while training the same way. The analysis found no evidence that the groups differed in muscle thickness, but moderate evidence that the 15% group increased its sum of skinfolds more than the maintenance group. Bench press was the one measure where the largest surplus showed an edge. Squat strength showed no group difference. The authors' conclusion is the sentence worth remembering: faster rates of body-mass gain primarily increase rates of fat gain rather than augmenting one-rep max or muscle thickness.[2] The job of nutrition is to make sure growth isn't limited by energy or protein. It isn't nutrition's job to force growth to go any faster.

A worked rate-of-gain table

The percentages are abstract until you see them as weekly numbers on a scale. Here's the same guidance turned into a rough gain target by training status, using an 80 kg lifter as the worked example.[1] Read it as a ceiling to stay under far more than a quota to hit: gaining a little slower than this is rarely a problem, but gaining much faster usually means extra fat.

Training status Target weekly gain For an 80 kg lifter Roughly per month
Novice (new to lifting) upper end, ~0.5% / week ~0.4 kg / week ~1.7 kg
Intermediate ~0.25–0.5% / week ~0.2–0.4 kg / week ~0.9–1.7 kg
Advanced (years trained) more conservative than 0.25–0.5% under ~0.2 kg / week under ~0.9 kg

Three things to read out of this table. First, the review gives a single 0.25–0.5% band for novice-and-intermediate lifters and says only that advanced lifters should be more conservative than that. The split into three rows is our practical reading of it. It isn't a set of published numbers.[1] Second, the numbers are total body weight. They aren't pure muscle: even a well-run lean gain includes some fat and some extra water and glycogen, so the muscle you're actually adding is slower still. Third, the 80 kg column is illustrative arithmetic (0.5% of 80 kg is 0.4 kg). Scale it to your own body weight, and treat any single week's number with suspicion. Weight bounces around day to day with food, salt, hydration and the bathroom: judge your rate by the trend over three to four weeks rather than any single weigh-in.

Where Strathlon fits. Strathlon is built to turn that "watch the trend" advice into something you can actually see. When you set a muscle-gain goal, the app puts a modest surplus target and a protein target in front of you each day, and the weight trend smooths out the daily noise so you can tell a real climb from a salty dinner. Log your strength sessions with Add activity and the day's calorie target adjusts around your training, so a heavy session day is met with a little more food. The app won't promise you a rate of muscle gain (no honest tool can), but it keeps the two dials that matter, energy and protein, honest and visible.

Protein: how much, and how to spread it

If energy is the permission to build muscle, protein is the building material. The off-season review advises bodybuilders to consume a minimum of 1.6 g/kg in the off-season, adding that targeting closer to 2.2 g/kg may ensure a more consistently optimised response, which is where the familiar 1.6–2.2 g of protein per kilogram of body weight per day comes from.[1] For an 80 kg person, that's about 130–175 g a day.

National guidance sits in much the same neighbourhood, and it's worth seeing more than one country's version of it. The International Society of Sports Nutrition (ISSN, United States) position stand describes 1.4–2.0 g/kg/day as sufficient for most exercising individuals.[5] The British Dietetic Association (United Kingdom) suggests that where muscle gain is the goal, resistance training plus a diet with adequate energy and carbohydrate as well as protein (approximately 1.6–1.7 g/kg/day) is what's required.[6] And the joint position statement of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine (United States and Canada) puts athletes' needs at 1.2–2.0 g/kg/day, with higher intakes indicated for short periods during intensified training or when reducing energy intake.[4] No one country's number is the last word, but they all tell the same story: comfortably more than a sedentary person eats, and nowhere near the amounts the supplement industry implies.

How you spread protein across the day matters a little too. A practical approach from the off-season review is to split your total across three to six meals of roughly 0.4–0.55 g/kg each: for an 80 kg lifter, that's very roughly 30–45 g of protein per meal, three or four times a day.[1] The joint US–Canada position statement frames the same habit as ingesting about 0.3 g/kg after key exercise sessions and every three to five hours across multiple meals.[4] This isn't a strict rule so much as a way to make hitting a high daily total easier and to keep muscle-building "topped up" through the day rather than crammed into one giant dinner.

Two honest limits. First, more is not better past this range: a meta-analysis of protein supplementation during resistance training found gains in fat-free mass plateaued at a total intake of about 1.6 g/kg/day (95% confidence interval 1.03 to 2.20), with intakes beyond that producing no further training-induced gains in fat-free mass.[7] Second, the exception is dieting: a systematic review of energy-restricted, resistance-trained lean athletes concluded protein needs are likely 2.3–3.1 g/kg of fat-free mass, scaled upwards with the severity of the restriction and with leanness.[8] For the everyday nutrition picture beyond muscle gain specifically, the eating-for-results guide goes wider, and how much protein do you really need digs into this number in depth.

Common misconception → correct it. "The more protein you eat, the more muscle you build." Only up to a point. Protein is essential and most people under-eat it rather than over-eat it, but the gains in fat-free mass from more protein plateau at around 1.6 g/kg/day, so once you're in the ~1.6–2.2 g/kg/day range with enough total energy and a real training stimulus, piling on extra protein doesn't build extra muscle. It's just expensive fuel.[7] Get enough, spread it out, and spend your attention on training progression and total energy instead.

Lean bulk vs dirty bulk

"Bulking" gets split into two caricatures. A lean bulk is the controlled version above (a modest surplus, a slow rate of gain, protein handled), accepting that muscle comes slowly in exchange for staying relatively lean. A dirty bulk is the opposite: eat big, don't count, let the scale fly up, and "clean it up later." The dirty bulk is tempting because fast scale gains feel like progress. The problem is that most of those fast gains aren't muscle.

There's good evidence for this. In a study of 39 elite athletes who all followed the same four-times-a-week strength programme for 8–12 weeks, one group was given a meal plan producing a positive energy balance and the other simply ate ad libitum, which left them in only a very small surplus. The counselled group ate about 600 kcal a day more, gained substantially more total weight (3.9% of body weight vs 1.5%) and far more fat mass (a 15% increase vs 3%), but the gain in lean body mass was not different between the groups.[9] In absolute terms, as the off-season review reports it, that was 1.7 kg of lean mass versus 1.2 kg (a difference that failed to reach statistical significance) against 1.1 kg of fat versus 0.2 kg, which did.[1] In plain terms: the extra calories bought a lot of extra fat and no clear extra muscle, and it's exactly that result the review draws on when it suggests 200–300 kcal rather than 500 for highly trained athletes.[1]

That's the whole case for lean over dirty. A bigger surplus doesn't appear to be convertible into more muscle: the controlled trial above found faster body-mass gain mainly speeds up fat accumulation[2], so the reliable effect of eating well past a modest surplus is simply more fat. And fat gained on a bulk has to be dieted off afterwards, which takes time in a deficit, where resting muscle protein synthesis is measurably lower.[3] A patient lean surplus tends to get you a similar amount of muscle with far less fat to reverse, meaning less of your year spent cutting and more of it spent growing.

Strathlon Add activity screen with a strength session being logged so the day's calorie target adjusts
Logging a strength session in Strathlon's "Add activity" flow. Recording training is what lets the app nudge the day's calorie target, so a hard session is fuelled without turning the whole week into a dirty bulk.
Common misconception → correct it. "Bulk hard now, cut later: it all evens out." It rarely evens out in your favour. A fast, fatty bulk means a longer, harder cut afterwards, and time spent aggressively cutting is time spent in the exact conditions where muscle is hardest to keep, let alone build. Two people who gain the same muscle end up in very different places if one did it lean and the other has 6 kg of extra fat to strip off. Slower and leaner is usually the faster route to looking muscular.

When appetite is the limit

For a good number of people the surplus is not hard to calculate. It is hard to eat. You get to eight in the evening still 400 kcal short, genuinely full, and the idea of another meal is unappealing. This is a recognised problem rather than a failure of willpower. A critical review of weight-gain recommendations for athletes and military personnel notes that a weekly gain of around 0.45 kg, mostly as lean mass, may be difficult for some athletes to achieve, and that the commonly recommended strategies for promoting a surplus, specifically larger portions, energy-dense foods, and prioritising liquid over solid, may prove helpful.[11]

Why food volume works against you. People tend to eat a fairly consistent weight of food rather than a consistent number of calories. In a controlled study where the energy density of meals was varied while everything else was held constant, participants ate the same weight of food across all three conditions, so their energy intake tracked the density: 1,800 kcal on the high-density days against 1,376 on the low-density ones, with no difference in reported hunger or fullness.[12] Four hundred kilocalories of difference, and nobody noticed. That mechanism is the whole reason big bulky salads and vegetable-heavy plates are so effective for fat loss, and the same reason they quietly sabotage a surplus.

Why liquid calories are the easy lever. Drinks are compensated for poorly. When people were given the same daily energy load either as a soft drink or as jelly beans for four weeks each, compensation for the solid form was near-total, while the liquid form produced almost none, and body weight rose only during the liquid period.[13] A second study matching beverage and solid forms of the same foods found total daily intake ran 12% to 19% higher on the beverage days regardless of which macronutrient was involved.[14] Read that as a warning if you are cutting. Read it as a tool if you are struggling to eat enough.

The honest caveat, because this is not unanimous: a review of the liquid-calorie satiety literature concluded the evidence remains inconclusive, with some studies finding solids less satiating.[15] The effect is real and well replicated. It is not a law.

What to actually do. Pick two or three additions and make them routine, rather than trying to eat more of everything:

Common misconception → correct it. "If I can't finish my calories, I just need to force it." Forcing an extra plate at the end of the day is the least sustainable version of this and the one people abandon first. The evidence points somewhere easier: keep the number of eating occasions the same and raise the energy density of the ones you already have.[11][12] The surplus you can hit every day beats the one you hit twice a week.

Building off-season, holding in-season

If you play a sport with a season, when you run a surplus matters as much as how big it is. The principle behind that is not folklore. The 2019 international consensus statement on nutrition for athletics states that periodised guidelines can be provided for the appropriate type, amount and timing of food and fluid intake across different scenarios of training and competition, and that each athlete should develop a personalised, periodised and practical nutrition plan.[16] The framework paper published alongside it sets out the same idea across the training year, the block and the day.[17]

Off-season and pre-season is when to build. A modest surplus plus consistent lifting is the combination covered in the rest of this guide, and the quieter months are when there is room for the slight rise in body fat that comes with it, and no match on Saturday that a heavy training week has to leave you fresh for.

In-season the job changes to fuelling and holding. Two lines of evidence make this a reasoned position rather than a preference. First, aggressive deficits cost lean mass: elite athletes losing weight at about 0.7% of body weight a week gained 2.1% in lean body mass, while those losing at 1.4% a week ended up unchanged, a significant difference between the groups.[18] Second, sustained low energy availability carries documented health and performance consequences, which is the subject of the International Olympic Committee's consensus statement on relative energy deficiency in sport.[19] Running a deficit through the block where your training load is highest is the situation those two findings meet in.

So in-season: eat around your matches, keep protein where it has been, and hold the composition work for the off-season. One honest limit on all of this, though. We could not find a study that directly tests losing fat in-season against doing it off-season and measures what happens to performance. The reasoning above is mechanism plus consensus rather than a trial, and it is worth pairing with the reminder from the same IOC work that body composition is one of an array of variables affecting performance and its influence should not be overstated.[20]

Honest expectations: muscle is slow

Everything above converges on one uncomfortable truth worth stating plainly: building muscle is slow, and eating more doesn't speed it up. At a target of 0.25–0.5% of body weight a week (and remembering that only part of that is muscle), meaningful, visible change is realistically a matter of months to years of consistent training and sensible eating. Newcomers get the fastest returns, because rates of muscle growth may slow as a lifter becomes more advanced, and then the pace tapers for everyone. That's normal. It doesn't mean anything's broken.[1]

A few things follow from that:

There's a freeing side to this. Because the surplus is small and the rate is slow, muscle gain doesn't require a dramatic diet: just a steady, slightly generous one, held long enough to matter. The hard part was never the eating. It's the patience.

Common questions

How big should my calorie surplus be to build muscle?

Modest. A narrative review of off-season nutrition for bodybuilders describes a hyper-energetic diet of roughly 10–20% above maintenance energy, which for a maintenance somewhere around 2,000–2,500 kcal works out to roughly an extra 200–500 kcal a day.[1] A separate review of the evidence lands in a similar place, advising a conservative surplus of about 1,500–2,000 kJ a day (roughly 360–480 kcal).[3] For highly trained athletes the off-season review notes that a 200–300 kcal daily surplus may be more appropriate than 500, to minimise unnecessary body-fat gain.[1] The practical test is your rate of weight gain over a few weeks rather than the exact calorie number, since maintenance is only ever an estimate.

How fast can I actually build muscle?

Slowly, and slower the more trained you are. A commonly cited target for gaining muscle while limiting fat is around 0.25–0.5% of body weight per week for novice-to-intermediate lifters: for an 80 kg person that's roughly 0.2–0.4 kg a week. Advanced lifters are advised to be more conservative with both the calorie surplus and the weekly weight gain, though the review doesn't put a specific number on how much more conservative. The same review notes that rates of muscle growth may slow as an individual becomes more advanced.[1] In an eight-week trial in resistance-trained lifters, a 15% surplus showed no evidence of a muscle-thickness advantage over a 5% surplus or over eating at maintenance, while adding the most to the sum of skinfolds, so eating more doesn't buy faster muscle gain.[2]

How much protein do I need to build muscle?

A frequently cited range for a muscle-building phase is roughly 1.6–2.2 g of protein per kilogram of body weight per day, spread across the day.[1] National and international bodies frame it a little differently: the International Society of Sports Nutrition (ISSN, United States) describes 1.4–2.0 g/kg/day as sufficient for most exercising individuals;[5] the joint position statement of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine (United States and Canada) gives 1.2–2.0 g/kg/day;[4] and the British Dietetic Association (United Kingdom) suggests approximately 1.6–1.7 g/kg/day alongside adequate energy and carbohydrate where muscle gain is the goal.[6] Splitting protein across three to six meals of roughly 0.4–0.55 g/kg each is a practical way to hit the total.[1] A meta-analysis of protein supplementation trials found no further gains in fat-free mass beyond a total intake of about 1.6 g/kg/day, with the upper bound of its confidence interval at 2.2 g/kg/day.[7]

Is a dirty bulk a bad idea?

Usually, yes, if muscle is the goal. A dirty bulk (eating in a large, uncontrolled surplus) makes the scale rise fast, but much of that fast gain is fat. In a study of 39 elite athletes doing the same four-a-week strength programme for 8–12 weeks, the group given a meal plan producing a positive energy balance gained more body weight (3.9% vs 1.5%) and far more fat mass (a 15% increase vs 3%) than the group eating ad libitum, yet the gain in lean body mass was not different between the groups.[9] A controlled lean surplus tends to deliver a similar amount of muscle with far less fat to diet off later.

Can I build muscle without a calorie surplus?

Sometimes, but it's harder. A review of the evidence concludes that muscle growth is possible in an energy deficit, but proposes this is more likely among people who are new to resistance training, overweight or obese, sometimes called body recomposition. For most trained lifters a small energy surplus is the usual advice, although the same review notes that the specific surplus needed to maximise muscle gain has not been established.[3] If you're dieting, prioritising protein (a systematic review of energy-restricted resistance-trained athletes puts likely needs at 2.3–3.1 g/kg of fat-free mass, scaling up with the severity of the deficit and with leanness[8]) and training hard helps protect the muscle you have.

I'm gaining weight but not looking more muscular: what's wrong?

The most likely explanation is that your surplus is too large, so a bigger share of the gain is fat rather than muscle, or that not enough time has passed to see the muscle underneath. Because muscle is built slowly, a sensible check is your rate of gain: if you're putting on much more than about 0.25–0.5% of body weight per week,[1] trimming the surplus usually improves the muscle-to-fat ratio. Also make sure the training is progressing and protein is adequate: food alone doesn't build muscle without a genuine training stimulus.

Takeaways

If you take one thing away, make it this: the nutrition of building muscle is a gentle, patient job. It isn't a feast. A small surplus, enough protein, a slow rate of gain, held steady for months: that's the whole recipe. Strathlon's part is to keep those dials visible and honest, adjusting your targets around the training you actually log, so the slow work of getting bigger is one less thing to guess at.

References

The figures in this guide come from the sources below. Where a number reflects established guidance rather than a single trial, the citation is to the position statement of the professional body that issued it, with the country it belongs to named: guidance differs a little between nations, and no one country's advice is the last word.

  1. Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports (Basel). 2019;7(7):154. PMC6680710 · PubMed 31247944
  2. Helms ER, Spence AJ, Sousa C, Kreiger J, Taylor S, Oranchuk DJ, Dieter BP, Watkins CM. Effect of small and large energy surpluses on strength, muscle, and skinfold thickness in resistance-trained individuals: a parallel groups design. Sports Medicine – Open. 2023;9(1):102. PMC10620361 · PubMed 37914977
  3. Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G, Iraki J. Is an energy surplus required to maximize skeletal muscle hypertrophy associated with resistance training? Frontiers in Nutrition. 2019;6:131. PMC6710320 · PubMed 31482093
  4. Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine joint position statement. Nutrition and athletic performance. Medicine & Science in Sports & Exercise. 2016;48(3):543–568. Issued jointly by the American College of Sports Medicine (United States), the Academy of Nutrition and Dietetics (United States) and Dietitians of Canada (Canada). PubMed 26891166 · doi:10.1249/MSS.0000000000000852
    A companion version of the same statement was published as: Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics. 2016;116(3):501–528. PubMed 26920240. The figures cited here are quoted from the Medicine & Science in Sports & Exercise version above.
  5. Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, et al. International Society of Sports Nutrition (ISSN, United States) position stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2017;14:20. PMC5477153 · PubMed 28642676
  6. British Dietetic Association (BDA, United Kingdom). Sport and exercise nutrition: Food Fact Sheet. bda.uk.com/resource/sport-exercise-nutrition.html
  7. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine. 2018;52(6):376–384. PubMed 28698222
  8. Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. International Journal of Sport Nutrition and Exercise Metabolism. 2014;24(2):127–138. PubMed 24092765
  9. Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. European Journal of Sport Science. 2013;13(3):295–303. PubMed 23679146
  10. Leaf A, Antonio J. The effects of overfeeding on body composition: the role of macronutrient composition — a narrative review. International Journal of Exercise Science. 2017;10(8):1275–1296. PMC5786199 · PubMed 29399253
  11. Larson-Meyer DE, Krason RK, Meyer LM. Weight Gain Recommendations for Athletes and Military Personnel: a Critical Review of the Evidence. Current Nutrition Reports. 2022;11(2):225–239. The source for appetite being a genuine limiter on achieving a surplus, and for larger portions, energy-dense foods and prioritising liquid over solid being the commonly recommended strategies that may help. PubMed 35233712
  12. Bell EA, Castellanos VH, Pelkman CL, Thorwart ML, Rolls BJ. Energy density of foods affects energy intake in normal-weight women. The American Journal of Clinical Nutrition. 1998;67(3):412–420. The controlled demonstration that people eat a consistent weight of food rather than a consistent number of calories: 1,800 kcal on high-energy-density days against 1,376 on low-density ones, with no difference in hunger or fullness. PubMed 9497184
  13. DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: effects on food intake and body weight. International Journal of Obesity and Related Metabolic Disorders. 2000;24(6):794–800. The same daily energy load given as a soft drink or as jelly beans for four weeks each. Compensation was near-total for the solid form and almost absent for the liquid one, with body weight rising only in the liquid period. PubMed 10878689
  14. Mourao DM, Bressan J, Campbell WW, Mattes RD. Effects of food form on appetite and energy intake in lean and obese young adults. International Journal of Obesity. 2007;31(11):1688–1695. Matched beverage and solid forms of the same foods, with total daily intake running 12% to 19% higher on the beverage days regardless of macronutrient. PubMed 17579632
  15. Almiron-Roig E, Chen Y, Drewnowski A. Liquid calories and the failure of satiety: how good is the evidence? Obesity Reviews. 2003;4(4):201–212. The dissenting review, carried deliberately: it concludes the liquid-versus-solid satiety evidence remains inconclusive, with some studies finding solids less satiating. PubMed 14649371
  16. Burke LM, Castell LM, Casa DJ, Close GL, Costa RJS, Desbrow B, et al. International Association of Athletics Federations Consensus Statement 2019: Nutrition for Athletics. International Journal of Sport Nutrition and Exercise Metabolism. 2019;29(2):73–84. Issued by the international governing body for athletics. The source for periodised nutrition guidance across training and competition scenarios, and for each athlete developing a personalised, periodised and practical plan. PubMed 30952204
  17. Stellingwerff T, Morton JP, Burke LM. A Framework for Periodized Nutrition for Athletics. International Journal of Sport Nutrition and Exercise Metabolism. 2019;29(2):141–151. The companion framework paper setting out nutritional periodisation across the training year, the block and the day. PubMed 30632439
  18. Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. International Journal of Sport Nutrition and Exercise Metabolism. 2011;21(2):97–104. Elite athletes losing at roughly 0.7% of body weight a week gained 2.1% in lean body mass, while those losing at 1.4% a week were unchanged. The source for slow loss protecting lean mass. PubMed 21558571
  19. Mountjoy M, Ackerman KE, Bailey DM, Burke LM, Constantini N, Hackney AC, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine. 2023;57(17):1073–1097. Issued by the International Olympic Committee (international). The documented health and performance consequences of sustained low energy availability, and the reason a deficit through a heavy competitive block is the wrong time for one. PubMed 37752011
  20. Mathisen TF, Ackland T, Burke LM, Constantini N, Haudum J, Macnaughton LS, et al. Best practice recommendations for body composition considerations in sport to reduce health and performance risks: a critical review, original survey and expert opinion by a subgroup of the IOC consensus on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine. 2023;57(17):1148–1158. The reminder carried here deliberately: body composition is one of an array of variables affecting performance, and its influence should not be overstated. PubMed 37752006

This is general educational information rather than medical, dietary or coaching advice. The figures here are drawn from published sports-nutrition consensus and are framed as population-level guides. Individual needs vary widely with training age, sex, genetics, starting body composition and health, and are best personalised with a qualified professional. Anyone with a health condition, a history of disordered eating, or who is pregnant or postpartum should consult a physician or registered dietitian before making changes to their diet or training. See our Terms for more.

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