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.
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
Unfortunately, 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?
Whether 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
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?
Wanting 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
To 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 often
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?
Since 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.
Meat
Choose 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
Fish
Choose 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
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
Eggs
All 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:
Like 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.
Fruit
Low-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).
Fats
There are many plant and animal fats that can be enjoyed on a healthy weight-gain diet.22
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
Drinks
Although drinking calories isn’t recommended for weight loss, consuming liquid calories may be useful for gaining weight. Some healthy ideas include:
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
Strength 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.
Finally, 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:
Add a big piece of cheese to your daily lunch.
Replace one drink of water each day with whole milk or coconut milk.
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.
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.
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]. ↩
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.
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?↩
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:
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. ↩
And don’t let their high cholesterol content worry you. Eating eggs doesn’t seem to raise cholesterol levels very much in most people:
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: