Hypertrophy Evidence Notes
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Gaining Weight with a Small Appetite

Most "can't gain weight" cases come down to how much you eat and to daily activity that rises without you noticing. Fill the gap with liquid calories and energy-dense food.

642Last reviewed Verdicts

Verdicts on this page12
  1. BProbably trueWhen people overeat by the same amount, weight and fat gain can differ several-fold between them. Genetics plays a part.
  2. DUncertain, inferenceIn free-living people, “can’t gain weight” is often explained by eating less than they think plus a rise in NEAT.
  3. BProbably trueResponses to resistance training also vary a lot between people, but gaining no muscle at all is rare.
  4. BProbably trueCalories from drinks make you less full than solid food, so you cut back less on other meals.
  5. BProbably trueRaising the energy density of meals or serving bigger portions increases intake. The two effects add up.
  6. CMay be trueEating the same food over and over makes it taste less good. More variety means you eat more.
  7. BProbably trueProtein is the most filling of the three macronutrients.
  8. DUncertain, inferenceIf you have a small appetite, keep protein at 1.6–1.8 g/kg and fill the rest with carbs and fat.
  9. CMay be trueEating more often does not raise appetite itself. But more chances to eat make it easier to eat more.
  10. BProbably trueExercise does not make you hungry afterward. If anything, it leaves you short by the calories you burned.
  11. CMay be trueWeight gainers work as a way to deliver calories. Their contents have no special effect.
  12. CMay be trueAim to gain 0.25–0.5% of body weight per week (0.18–0.35kg per week at 70kg). A larger surplus mostly becomes fat.

Bottom line

  • The “hardgainer” is half true. People who overeat by the same amount gain very different amounts. But the cause is usually not a fast metabolism. It is how much you eat and daily activity that rises without you noticing when you overeat (NEAT: non-exercise activity such as walking, standing, and fidgeting)
  • Almost no one fails to respond to resistance training at all
  • Make up missing calories by drinking them. Liquids fill you up less than solids
  • Add energy-dense foods like oil, nuts, cheese, and dried fruit. Use bigger portions and more dishes
  • Keep protein at 1.6–1.8 g/kg (112–126g at 70kg). More than that fills you up and makes it harder to hit your total calories
  • Aim for +0.2–0.35kg per week in body weight (7-day average). If you fall short, add 150–200 kcal every 2–3 weeks

Is there a “can’t gain weight” body type?

BProbably true

When people overeat by the same amount, weight and fat gain can differ several-fold between them. Genetics plays a part.

  • In 16 people who ate 1,000 kcal a day extra for 8 weeks, fat gain varied about 10-fold. About 2/3 of the extra expenditure came from NEAT, and those whose NEAT rose more gained less fat (r=0.77, Levine 1999)
  • In a study that overfed 12 pairs of identical twins the same amount, weight gain ranged from 4.3 to 13.3kg, about a 3-fold spread. Gains were similar within each pair (Bouchard 1990)
  • A review of 16 overfeeding experiments found inconsistent evidence that the body burns off surplus energy to resist weight gain (adaptive thermogenesis) (Joosen & Westerterp 2006)
  • Raising body weight above its starting point also raises energy expenditure (Leibel 1995)

DUncertain, inference

In free-living people, “can’t gain weight” is often explained by eating less than they think plus a rise in NEAT.

No study has directly separated appetite from metabolism as the cause. This is an inference from the studies above. To check, log your intake and your daily body weight. If your log shows you eating +300–500 kcal more but your 7-day average weight has not moved for 3 weeks, add more.

BProbably true

Responses to resistance training also vary a lot between people, but gaining no muscle at all is rare.

  • In a study of 585 people training for 12 weeks, the change in arm muscle cross-sectional area ranged from −2% to +59% (Hubal 2005)
  • In a study of 287 people, muscle size changed by 4.8% on average, ranging from −11% to +30% (Ahtiainen 2016)

How to get more calories in

BProbably true

Calories from drinks make you less full than solid food, so you cut back less on other meals.

  • In a trial that added about 450 kcal a day for 4 weeks, adding jelly beans (solid) led people to eat that much less of other food, and weight did not rise. Adding soda (liquid) did not reduce other food, and weight went up (DiMeglio & Mattes 2000)
  • At the same 300 kcal, drinks produced the least fullness and the shortest time until the next meal (Mattes & Campbell 2009)
  • A systematic review of 253 trials found that food form and the time until the next meal explained about half of the variation in compensation. Solids or semi-solids eaten 30–120 minutes before a meal reduced that meal the most (Almiron-Roig 2013)

Drink shakes with meals or between meals. Avoid them right before a meal.

BProbably true

Raising the energy density of meals or serving bigger portions increases intake. The two effects add up.

  • At the same weight of food, a more energy-dense diet raised daily intake from 1,376 to 1,800 kcal (Bell 1998)
  • Portions 1.5 times larger raised daily intake by 16%, or +504 kcal in men. Doubling portions raised it by 26% (Rolls 2006a)
  • The effects of portion size and energy density added up and persisted across meals (Rolls 2006b, Kral 2004)

Most subjects were normal-weight to overweight women, and the studies lasted only days. Applying this to lean men involves some inference.

CMay be true

Eating the same food over and over makes it taste less good. More variety means you eat more.

This is called sensory-specific satiety (Rolls 1981). Put several dishes on the table at each meal, add a dessert, or change flavors.

BProbably true

Protein is the most filling of the three macronutrients.

DUncertain, inference

If you have a small appetite, keep protein at 1.6–1.8 g/kg and fill the rest with carbs and fat.

Muscle gains mostly plateau at about 1.6 g/kg (Protein). Beyond that, you only get fuller and find it harder to hit your total calories. This is an inference from the two findings above.

CMay be true

Eating more often does not raise appetite itself. But more chances to eat make it easier to eat more.

  • A review of controlled feeding studies found that eating more than 3 times a day did little for appetite control (Leidy 2011)
  • Appetite was higher with more frequent eating (Perrigue 2016)
  • A meta-analysis of observational studies found that people who ate more often took in about 125 kcal more per day (Wang 2016)

BProbably true

Exercise does not make you hungry afterward. If anything, it leaves you short by the calories you burned.

  • In a meta-analysis of 29 studies, intake after a single exercise session barely changed (effect size 0.14). People did not eat back what they burned, so the net result was a large calorie deficit (effect size −1.35, Schubert 2013)
  • A review reaches the same conclusion (Dorling 2018). Responses vary between people (Goltz 2018)

After training, drink a shake without waiting to get hungry.

Weight gainers

CMay be true

Weight gainers work as a way to deliver calories. Their contents have no special effect.

In 73 people training for 8 weeks, the group that drank a gainer of about 2,000 kcal a day gained 3.1kg, more than the group that did not. The protein content of the gainer did not affect the results (Rozenek 2002). The gain in lean mass may include glycogen and water. A homemade shake does the same thing, and you choose what goes in it.

How fast to gain

CMay be true

Aim to gain 0.25–0.5% of body weight per week (0.18–0.35kg per week at 70kg). A larger surplus mostly becomes fat.

  • The recommendation is 0.25–0.5% per week, at maintenance calories +10–20% (Iraki 2019)
  • In elite athletes, the group that ate more under nutritional guidance (about 3,585 kcal) gained 3.9% body weight and 15% fat. The group that ate on their own (about 2,964 kcal) gained 1.5% body weight and 3% fat. Lean mass gains were the same (Garthe 2013)
  • For details, see Bulk, Cut, or Recomp

References

  1. Levine JA et al. 1999. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science. PMID 9880251 ↩
  2. Bouchard C et al. 1990. The response to long-term overfeeding in identical twins. N Engl J Med. PMID 2336074 ↩
  3. Joosen AM, Westerterp KR. 2006. Energy expenditure during overfeeding. Nutr Metab (Lond). PMID 16836744 ↩
  4. Leibel RL et al. 1995. Changes in energy expenditure resulting from altered body weight. N Engl J Med. PMID 7632212 ↩
  5. Hubal MJ et al. 2005. Variability in muscle size and strength gain after unilateral resistance training. Med Sci Sports Exerc. PMID 15947721 ↩
  6. Ahtiainen JP et al. 2016. Heterogeneity in resistance training-induced muscle strength and mass responses in men and women of different ages. Age (Dordr). PMID 26767377 ↩
  7. DiMeglio DP, Mattes RD. 2000. Liquid versus solid carbohydrate: effects on food intake and body weight. Int J Obes Relat Metab Disord. PMID 10878689 ↩
  8. Mattes RD, Campbell WW. 2009. Effects of food form and timing of ingestion on appetite and energy intake in lean young adults and in young adults with obesity. J Am Diet Assoc. PMID 19248858 ↩
  9. Almiron-Roig E et al. 2013. Factors that determine energy compensation: a systematic review of preload studies. Nutr Rev. PMID 23815144 ↩
  10. Bell EA et al. 1998. Energy density of foods affects energy intake in normal-weight women. Am J Clin Nutr. PMID 9497184 ↩
  11. Rolls BJ et al. 2006a. Larger portion sizes lead to a sustained increase in energy intake over 2 days. J Am Diet Assoc. PMID 16567150 ↩
  12. Rolls BJ et al. 2006b. Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake. Am J Clin Nutr. PMID 16400043 ↩
  13. Kral TV et al. 2004. Combined effects of energy density and portion size on energy intake in women. Am J Clin Nutr. PMID 15159224 ↩
  14. Rolls BJ et al. 1981. Sensory specific satiety in man. Physiol Behav. PMID 7267792 ↩
  15. Dhillon J et al. 2016. The Effects of Increased Protein Intake on Fullness: A Meta-Analysis and Its Limitations. J Acad Nutr Diet. PMID 26947338 ↩
  16. Westerterp-Plantenga MS et al. 2009. Dietary protein, weight loss, and weight maintenance. Annu Rev Nutr. PMID 19400750 ↩
  17. Westerterp-Plantenga MS et al. 2012. Dietary protein – its role in satiety, energetics, weight loss and health. Br J Nutr. PMID 23107521 ↩
  18. Paddon-Jones D et al. 2008. Protein, weight management, and satiety. Am J Clin Nutr. PMID 18469287 ↩
  19. Leidy HJ et al. 2011. The effect of eating frequency on appetite control and food intake: brief synopsis of controlled feeding studies. J Nutr. PMID 21123467 ↩
  20. Perrigue MM et al. 2016. Higher Eating Frequency Does Not Decrease Appetite in Healthy Adults. J Nutr. PMID 26561409 ↩
  21. Wang YQ et al. 2016. Increased Eating Frequency Is Associated with Lower Obesity Risk, But Higher Energy Intake in Adults: A Meta-Analysis. Int J Environ Res Public Health. PMID 27322302 ↩
  22. Schubert MM et al. 2013. Acute exercise and subsequent energy intake. A meta-analysis. Appetite. PMID 23274127 ↩
  23. Dorling J et al. 2018. Acute and Chronic Effects of Exercise on Appetite, Energy Intake, and Appetite-Related Hormones. Nutrients. PMID 30131457 ↩
  24. Goltz FR et al. 2018. Interindividual Responses of Appetite to Acute Exercise. Med Sci Sports Exerc. PMID 29240652 ↩
  25. Rozenek R et al. 2002. Effects of high-calorie supplements on body composition and muscular strength following resistance training. J Sports Med Phys Fitness. PMID 12094125 ↩
  26. Iraki J et al. 2019. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports (Basel). PMID 31247944 ↩
  27. Garthe I et al. 2013. Effect of nutritional intervention on body composition and performance in elite athletes. Eur J Sport Sci. PMID 23679146 ↩