How to gain weight on low-carb or keto

How to gain weight on low carb or keto

Do you want to gain weight? Since most nutrition articles focus on fat loss, you may feel as though you’re in the minority.

The usual advice for weight gain is to eat a higher amount of carbohydrates to “bulk up.” Unfortunately, this may lead to gaining mainly fat mass.1

Although most people see low carb as a weight-loss diet, this isn’t necessarily true. Low carb tends to lead to weight loss in people with excess weight because it helps them feel full and they end up eating less.2

However, low-carb foods are very nutrient dense, and may potentially help people who are underweight gain lean mass. Eating low carb, and eating when hungry, can be considered a weight-normalizing lifestyle.

In this guide, you’ll learn how to gain weight the healthy way on a low-carb or keto diet.

  1. Why do people want to gain weight?
  2. How to gain weight on low carb
  3. Healthy weight-gain foods
  4. Building muscle on low carb
  5. 15 quick weight-gain hacks
  6. More resources

1. Why do people want to gain weight?

While some people may just want to add a few extra pounds to a lean frame, others may wish to build muscle and increase their overall size.

So, what are the reasons people want to gain weight? Here are a few of the more common ones:3

  • Gain more strength
  • Improve sports performance
  • Combat age-related muscle loss
  • Improve self-confidence
  • To possibly improve overall health (in those who are very thin)


Problems caused by pressure to gain weight

untitled-2-7-1600x1424Unfortunately, this desire for weight gain often causes problems. This is especially true for younger men.

In one study, 7.6% of teens and young men reported taking weight-gain products deemed “potentially unhealthy” — including creatine supplements and anabolic steroids — in order to gain weight.4

Generally speaking, women seem more willing to take products to lose weight.5 On the other hand, men may potentially be more likely to take a rapid weight-gain product without concern for safety.

The reason? To get bigger quickly.

We certainly do not recommend taking steroids or questionable weight-gain supplements to add pounds. Fortunately, there are healthier, more sustainable ways to gain weight.

Is being underweight unhealthy?

untitled-4Whether being underweight is unhealthy depends on the reason a person is underweight.

Several medical conditions, especially cancer and gastrointestinal diseases, can lead to weight loss. Also, some medications are associated with loss of weight either directly or through appetite suppression.

Being underweight (having a BMI below 18.5) is associated with a somewhat shorter life, especially in older adults.6

Yet it’s generally very hard to determine if this is due to underlying disease or if being underweight in itself is potentially dangerous. One possible reason for the latter could be that people who are underweight have fewer reserves in case of severe illness. In addition, lower weight could signify lower muscle mass and a higher risk of frailty.7

Being underweight due to an eating disorder like anorexia nervosa is dangerous, as well as the cause of much suffering. It’s extremely important to seek professional help in such a situation.

Many people who want to gain weight are likely still within the lower to middle range of a normal BMI (18.5 to 25). While this isn’t a dangerous or unhealthy weight, some people within this range may want to gain some lean mass.

2. How to gain weight the healthy way

healthy eating, diet, gesture and people concept - close up of m

How and what you eat aren’t the only factors involved in weight gain. Exercise, sleep, and stress can also play important roles, and should be emphasized for healthy weight gain.

However, in the following section, we’ll focus first on the non-exercise strategies to gain in a healthy manner.

What is the fastest way to gain weight?

untitled-6Wanting to gain weight fast is completely understandable. However, it’s unlikely to be sustainable or healthy.8 Slow and steady wins the race.

Ultra-high-calorie bulking diets can work very well for quick weight gain in some people. But typically these individuals are extremely active bodybuilders or athletes who don’t mind gaining fat in addition to muscle.9

With this kind of diet, people tend to load up on hundreds of extra calories and carbohydrates per day in addition to dramatically increasing their protein intake. It works, but it usually comes with some fat gain.10

There’s an even worse fast way: Eat ice cream and cookies constantly between meals, and wash it down with soda. While you’ll probably gain weight fairly rapidly, you’ll likely gain fat mainly around your abdomen and liver, increasing your risk of type 2 diabetes, fatty liver disease, and other health problems.11

There’s a difference between gaining weight in the fastest way and increasing in size in the healthiest way possible.

Optimal nutrition to support lean weight gain

Fried breakfast with egg, sausages and baked tomatoTo gain lean weight in a healthy way, you need to emphasize food quality.

Nutrient density refers to how nutritious your foods are and the amount of beneficial protein, vitamins, and minerals present in them. There’s far too much focus on calorie counting and not enough focus on maximizing nutrient intake.12

As an example, 500 calories from white rice and 500 calories from an avocado and three eggs are entirely different. Yes, they have the same amount of energy, but avocado and eggs are far superior in nutritional value.

While rice provides lots of rapidly digested carbohydrates and not much else, eggs contain high-quality protein and other nutrients needed to build lean body mass, while avocados are rich in healthy fats, potassium, and fiber.

Eat oftenTable of Italian food

To lose weight, one of the most effective ways is to eat less often – also called intermittent fasting.

Not surprisingly, if you’re finding it hard to gain weight, you should not do intermittent fasting. In fact, you should likely aim to do the opposite: Eat often.13

If you are going to increase your snacking to increase your food frequency, make sure you are choosing healthy snack options.

Do sleep and stress affect weight gain?

Businessman with face pressed against wall, profile, close-upSince your muscles recover and grow during sleep, it’s essential to make sure you spend enough time asleep.14 In fact, sleep and stress share an intrinsic connection; if you are sleep-deprived, you are much more likely to be stressed.

It’s well-known that lack of sleep and stress raises cortisol levels.15 Unfortunately, higher cortisol levels have a negative impact on gaining weight in a healthy way. They may lead to putting on fat rather than lean mass.

Higher cortisol levels both directly and indirectly influence fat gain, through overeating and the tendency to crave junk food.16

To be in optimal condition and promote healthy gains in lean mass, aim to:

  • Sleep 7 to 9 hours per night
  • Find time to relax and enjoy life
  • Socialize with family and friends rather than remain isolated
  • Prevent overtraining (exercising too much)

3. Healthy foods for weight gain


First of all, we believe the cornerstones of a healthy diet should remain the same. The staple food groups of your diet should be high-quality protein sources, low-carb vegetables, and low-sugar fruits.

However, try to emphasize the most energy-dense options to encourage weight gain. See our list below.



Tender steak medallions topped with cheese on wooden boardsChoose a variety of cuts of meat, including red meat.17 Here are some of the best choices:

  • Bacon (ideally traditionally cured)
  • Beef (ribs are particularly good)
  • Chicken (including skin)
  • Lamb
  • Pork (of all varieties – pork belly included)
  • Sausages (check ingredients list for added sugar)
  • Steak


Salmon fillet with fresh healthy herbs,vegetables, oil and spicesChoose oily or fatty types whenever possible. First of all, because of the extra fat, it provides more calories. Secondly, they are a great source of essential omega-3 fats.18

Top fatty fish choices:

  • Anchovies
  • Mackerel
  • Salmon
  • Sardines
  • Trout

Not only are these fish highest in omega-3, but they are also among the lowest-mercury commercial fish.



Cheese and other high-fat, low-carb dairy products are delicious and satisfying. Contrary to the low-fat dietary recommendations of the past few decades, the latest research shows that cheese has neutral or possibly beneficial effects on health.19

Dairy-based foods are great for weight gain because they are both nutritious and energy-dense. You can include the following dairy foods in your weight-gaining diet:

  • Cheese (all types)
  • Greek yogurt
  • Whole milk20


French omelet with herbs, stuffed with mushrooms and onionsAll in all, eggs are one of the most nutrient-dense foods on earth.21

Due to their high fat, protein, vitamin, and mineral content, they are perfect for healthy weight gain. One of the great things about eggs is that you can prepare them in so many different ways, and each one can feel like a whole new food. So feel free to include lots of them in your diet:


Produce aisle in supermarket, close-upLike the other food groups, nutrient density should be emphasized with vegetables too.

Any vegetable is a great addition to your meal, but you have a choice to make regarding starchy vegetables like potatoes, sweet potatoes, and other root vegetables. These tend to be higher in carbohydrates.

Adding a lot of starches to a calorie-dense diet full of healthy fat will increase the speed of weight gain – a good thing. However, this might potentially increase the likelihood of more fat gain too. Therefore, depending on your aims and objectives, it’s your choice whether you want to go higher carb or not.


Fresh avocadoLow-sugar fruit can be beneficial on a weight-gain diet. Besides being high in nutrients, avocados and olives are very energy-dense, which makes them an excellent choice.

Berries are another great fruit to include. Combine berries with heavy cream for a delicious, energy-dense snack or dessert.

Eating a moderate amount of sweeter fruits, like apples and bananas, can also be fine if you’re trying to gain weight, unless you have specific health-related reasons to stay very low carb, such as diabetes).


untitled-14There are many plant and animal fats that can be enjoyed on a healthy weight-gain diet.22

Most noteworthy are the following options:

  • Butter
  • Cream
  • Ghee
  • Lard
  • Tallow
  • Avocado oil
  • Coconut oil
  • Olive oil
  • Dark chocolate (preferably 85% or above)
  • Nuts

Not only will these foods help you gain weight, but some may also provide you with health benefits. For instance, avocado, chocolate, nuts, and olives have been associated with decreased cardiovascular risk in high-quality studies.23


Coffee artAlthough drinking calories isn’t recommended for weight loss, consuming liquid calories may be useful for gaining weight. Some healthy ideas include:

4. Can you build muscle on a low-carb diet?

It’s definitely possible to increase muscle mass while eating low carb.

In fact, in their position paper on diets and body composition, the International Society for Sports Nutrition (ISSN) states that a range of dietary patterns — including keto and low-carb diets — can be successful for building muscle, as long as adequate protein and calories are consumed.24

Evidence for weight gain with a low-carb diet

An interesting study from 2014 investigated the effects of a ketogenic diet vs. a standard high-carbohydrate diet on body composition.

Twenty-six resistance-trained men participated in the study. After 11 weeks, the men in the keto group gained more lean mass and lost more fat mass than those in the control group.25

In a 10-week study of athletic men from 2017, those who ate a very-low-carb diet diet gained a similar amount of muscle and lost slightly more fat than those who followed a higher-carb diet.26

Resistance training and heavy lifting for weight gain

weightlifting strong man on a gymStrength training and lifting heavy weights both stimulate muscular growth and have a broad range of benefits for the body in general. While a healthy, optimized diet provides the nutritional building blocks for weight gain, resistance training is necessary for building muscle and increasing lean mass.27

Right away, let’s shoot one myth down; you don’t need to spend hours at the gym every day to gain muscle. An intense training session two or three times per week is more than enough to stimulate plenty of muscle growth. 28

If you have access to a gym or home exercise equipment, consider emphasizing compound exercises such as bench press, deadlifts, and squats. Compound exercises stimulate more muscle fibers than isolated exercises.

Learn more in our exercise and health guide.

5. 15 quick weight-gain hacks

raspberryFinally, if you still can’t gain weight, here are 15 ideas that may help. But unless you’re in training to be a sumo wrestler, don’t implement all of them at once! Try a few at a time:

  1. Add a big piece of cheese to your daily lunch.
  2. Replace one drink of water each day with whole milk or coconut milk.
  3. Add a serving of low-carb granola at breakfast.
  4. Drink hot chocolate each day made from coconut milk and cocoa powder.
  5. Add cream to your tea/coffee. If you already do, then double it.
  6. Eat an avocado every day.
  7. Add a few tablespoons of your favorite oil to your meal, such as coconut, macadamia, or olive oil.
  8. Sleep for longer than you have been doing, whenever possible.
  9. Eat fatty cuts of meat rather than lean cuts.
  10. Melt some cheese on top of your dinner each day.
  11. Eat an additional bowl of berries, covered with heavy cream and dark chocolate shavings.
  12. Include an extra handful of nuts in your daily diet.
  13. If you drink black coffee, replace it with a latte.
  14. Make some chocolate-fat bombs.
  15. Add more carbohydrate: emphasize higher quality, nutrient-dense carbs, such as sweet potatoes.

Final thoughts

Contrary to popular belief, high-carb intake isn’t necessary to gain weight.

If you want to be a bodybuilder with a massive physique, then consuming lots of carbohydrates will get you there quicker. But that’s not what this article is about.

A healthy diet based on nutritious food can help you gain weight the healthy way – and low or moderate carbohydrate intake is entirely compatible with this goal.

6. More

About the author

Michael Joseph is a nutrition educator with a strong focus on health optimization through real food and a healthy lifestyle. He holds a Master’s degree in Nutrition Education and runs the popular website Nutrition Advance.

This page is based on the article ‘How to Gain Weight the Healthy Way‘ on Nutrition Advance. Editing and fact-checking by Andreas Eenfeldt, MD and Bret Scher MD.

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How to gain weight on low-carb or keto - the evidence

This guide is written by Dr. Andreas Eenfeldt, MD and was last updated on June 17, 2022. It was medically reviewed by Dr. Bret Scher, MD on August 17, 2020.

The guide contains scientific references. You can find these in the notes throughout the text, and click the links to read the peer-reviewed scientific papers. When appropriate we include a grading of the strength of the evidence, with a link to our policy on this. Our evidence-based guides are updated at least once per year to reflect and reference the latest science on the topic.

All our evidence-based health guides are written or reviewed by medical doctors who are experts on the topic. To stay unbiased we show no ads, sell no physical products, and take no money from the industry. We're fully funded by the people, via an optional membership. Most information at Diet Doctor is free forever.

Read more about our policies and work with evidence-based guides, nutritional controversies, our editorial team, and our medical review board.

Should you find any inaccuracy in this guide, please email

  1. American Journal of Clinical Nutrition 2003: Hepatic de novo lipogenesis in normoinsulinemic and hyperinsulinemic subjects consuming high-fat, low-carbohydrate and low-fat, high-carbohydrate isoenergetic diets [nonrandomized study, weak evidence]

    The American Journal of Clinical Nutrition 1988: Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man [nonrandomized study, weak evidence]

  2. Obesity Reviews 2015: Do ketogenic diets really suppress appetite? A systematic review and meta-analysis [strong evidence]

    Annals of Internal Medicine 2005: Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes [non-randomized trial; weak evidence]

  3. This is based on consistent clinical experience of low-carb practitioners. [weak evidence]

  4. JAMA Pediatrics 2014: Prospective associations of concerns about physique and the development of obesity, binge drinking, and drug use among adolescent boys and young adult men [observational study with OR >2; weak evidence]

  5. In a 2007 survey, 20.6% of women and 9.7% of men reported having taken weight-loss supplements:

    Journal of the American Dietetic Association 2007: Use of nonprescription dietary supplements for weight loss is common among Americans [cross-sectional survey; weak evidence]

  6. The American Journal of Clinical Nutrition 2014: BMI and all-cause mortality in older adults: a meta-analysis[meta-analysis of observational studies with RR <2; very weak evidence]

    Obesity 2012: BMI and mortality: results from a national longitudinal study of Canadian adults[observational study with RR <2; very weak evidence]

  7. Age and Ageing 2015: Prevalence of frailty and disability: findings from the English Longitudinal Study of Ageing [observational study, weak evidence]

  8. This is based on consistent clinical experience of low-carb practitioners. [weak evidence]

  9. International Journal of Exercise Science 2017: The Effects of Overfeeding on Body Composition: The Role of Macronutrient Composition – A Narrative Review [overview article; ungraded]

  10. Obesity 2018: High fat and sugar consumption during ad libitum intake predicts weight gain [nonrandomized study, weak evidence]

  11. The American Journal of Clinical Nutrition 2012: Sucrose-sweetened beverages increase fat storage in the liver, muscle, and visceral fat depot: A 6-mo randomized intervention study [randomized trial; moderate evidence]

    American Journal of Clinical Nutrition 2003: Hepatic de novo lipogenesis in normoinsulinemic and hyperinsulinemic subjects consuming high-fat, low-carbohydrate and low-fat, high-carbohydrate isoenergetic diets [nonrandomized study, weak evidence]

  12. This is based on clinical experience of low-carb practitioners and was unanimously agreed upon by our low-carb expert panel. You can learn more about our panel here [weak evidence].

  13. Surprisingly, there isn’t high quality evidence to support eating more often for increased muscle gain. However, the following article makes a case for ensuring adequate protein intake over at least four distinct meals each day.

    Journal of the International Society of Sports Nutrition 2018: How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution [overview article; ungraded]

  14. Medical Hypotheses 2011: Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis [overview article; ungraded]

  15. Journal of Clinical Neurology 2012: Adverse effects of 24 hours of sleep deprivation on cognition and stress hormones [nonrandomized study, weak evidence]

  16. Obesity (Silver Spring) 2017: Stress, cortisol, and other appetite-related hormones: Prospective prediction of 6-month changes in food cravings and weight [non-controlled study; weak evidence]

  17. Meat is an excellent source of protein and many important vitamins and minerals. The evidence linking red meat to heart disease, cancer, and other health issues is very weak: Guide to red meat: is it healthy?

  18. Choosing wild-caught fish may be best. Studies suggest that farmed fish may often have higher levels of pollutants and can be lower in omega-3 fats:

    Public Health Reviews 2018: Food safety impacts of antimicrobial use and their residues in aquaculture[overview article; ungraded]

    Science 2004: Global assessment of organic contaminants in farmed salmon [observational study; weak evidence]

    Scientific Reports 2016: Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006–2015 [non-controlled study; weak evidence]

  19. The British Journal of Nutrition 2013: Effects of low-fat or full-fat fermented and non-fermented dairy foods on selected cardiovascular biomarkers in overweight adults [randomized trial; moderate evidence]

    The American Journal of Clinical Nutrition 2016: High intake of regular-fat cheese compared with reduced-fat cheese does not affect LDL cholesterol or risk markers of the metabolic syndrome: a randomized controlled trial [randomized trial; moderate evidence]

    The American Journal of Clinical Nutrition 2015: Diets with high-fat cheese, high-fat meat, or carbohydrate on cardiovascular risk markers in overweight postmenopausal women: a randomized crossover trial [randomized trial; moderate evidence]

  20. Milk contains 12 grams of carbs per cup, so you may be able to include moderate amounts for weight gain. However, it’s best to avoid if you’re eating a keto diet for diabetes or other health concerns.

  21. And don’t let their high cholesterol content worry you. Eating eggs doesn’t seem to raise cholesterol levels very much in most people:

    Nutrients 2018: Dietary cholesterol contained in whole eggs is not well absorbed and does not acutely affect plasma total cholesterol concentration in men and women: results from 2 randomized controlled crossover studies [moderate evidence]

  22. Do you worry about eating butter, cream, coconut oil, and other sources of saturated fat? While still somewhat controversial, several systematic reviews have shown little to no benefit from avoiding saturated fats or replacing them with unsaturated fats:

    Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]

    Annals Nutrition & Metabolism 2009: Dietary fat and coronary heart disease: Summary of evidence from prospective cohort and randomised controlled trials [moderate evidence]

    Read more in our user guide to saturated fat

  23. The Journal of Nutrition 2020: A moderate-fat diet with one avocado per day increases plasma antioxidants and decreases the oxidation of small, dense LDL in adults with overweight and obesity: a randomized controlled trial [moderate evidence]

    Journal of Nutrition 2016: Cocoa flavanol intake and biomarkers for cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials [strong evidence]

    Nutrients 2017: Nuts and human health outcomes: a systematic review [strong evidence]

    Annals of Internal Medicine 2006:The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial [moderate evidence]

  24. Journal of the International Society for Sports Nutrition 2017: International society of sports nutrition position stand: diets and body composition
    [position statement; ungraded]

  25. Journal of the International Society of Sports Nutrition 2014: The effects of ketogenic dieting on skeletal muscle and fat mass [non-randomized study; weak evidence]

  26. Journal of Strength and Conditioning Research 2017: The effects of ketogenic dieting on body composition, strength, power, and hormonal profiles in resistance training males
    [non-randomized study; weak evidence]

  27. Journal of Strength and Conditioning Research 2005: Training leading to repetition failure enhances bench press strength gains in elite junior athletes. [observational study, weak evidence]

  28. In fact, this study showed equal muscle growth training once weekly or three days per week.

    International Journal of Exercise Science 2016: Increasing lean mass and strength: A comparison of high frequency strength training to lower frequency strength training [randomized trial; moderate evidence]