How to gain weight on low-carb or keto

How to gain weight on low carb or keto

Do you want to gain weight? Given how most nutrition articles focus on fat loss, maybe you feel in a minority there.

The usual advice for weight gain is to eat a higher amount of carbohydrates to “bulk up” and adopt an exercise program. Unfortunately it often results in mainly gaining fat mass, and is not necessarily healthy.

This page will examine how to gain weight the healthy way, while staying on a low-carb diet, and has the following subsections:

  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. How to overcome difficulty gaining weight
  6. More resources

Low-carb for weight gain?

While most people see a low-carb diet as a weight-loss diet, this is not necessarily true. Low carb tends to lead to weight loss for people with excess weight, due to increased satiety and fat burning.

However, low-carb foods are very nutrient dense, and can assist lean weight gain in people who are underweight. Eating low carb, and eating when hungry, can be considered a weight-normalizing diet (or lifestyle).


1. Why do people want to gain weight?

It’s true that most people today are looking to lose weight, but some also want to gain weight.

While the majority just want to add a few extra pounds to a skinny frame, others wish to build muscle and increase in size.

So, what are the reasons people want to gain weight? That depends on the goal, but here are several:

  • Gain more strength
  • Sporting objectives
  • For better metabolic health (muscles burn more fat)
  • Combat aging (muscle-density loss is a natural side effect)
  • Improve self-confidence
  • To possibly improve overall health (in those who are too skinny)

All of these are understandable aims where weight gain could possibly benefit someone’s life.


Problems caused by pressure to gain weight

untitled-2-7-1600x1424Unfortunately, this desire for weight gain often causes problems. This is especially the case in young men, with more than 8.5% of people extremely concerned about their body shape. Out of this group, more than 7.6% of adolescents and young men were taking “potentially dangerous” products every month to gain weight.

Also, new research shows that males who are obsessed with their physique and exhibit “high concerns over thinness” have a much greater future risk for binge eating, obesity and drug use.

Generally speaking, it tends to be women who go to extremes and take unhealthy products to lose weight. On the other hand, men are much more likely to take some quick fix weight-gain product without concern for safety.

The reason? To get bigger quickly. Therefore it’s not surprising to see that 11% of teenagers in US schools reported having used Human Growth Hormone (HGH), and 7% also admitted to using steroids in the past to bulk up.

Taking drugs is clearly not a healthy way to gain weight. Fortunately there are better ways to do it.

Is being underweight unhealthy?

untitled-4Whether being underweight is unhealthy depends on the reason for being underweight. Several medical conditions, especially cancer and gastrointestinal diseases, can lead to weight loss. Also, some medication is associated with loss of weight either directly or through appetite suppression. Finally, smoking is an unhealthy habit that is connected to a lower weight.

Being underweight (having a BMI below 18.5) is associated with a somewhat shorter life.1 It’s generally very hard to determine if this is due to underlying disease, or habits like smoking, or if being underweight in itself is potentially dangerous. One possible reason for the latter could be that people who are underweight have fewer resources in case of severe illness.

Being underweight due to an eating disorder like anorexia nervosa is dangerous, as well as the cause of much suffering. We recommend seeking professional help in such a situation.

Most people who want to gain weight are likely still within the normal range of BMI (18.5 – 25). This is not a dangerous or unhealthy weight, and it is considered quite normal. So for people who want to gain weight it’s a good idea to attempt to do it in a healthy way. Keep reading to get to know how to do it.



2. How to gain weight the healthy way

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

Now that we have looked into some of the reasons we may want to gain weight, how can we do it in a healthy way? Diet predominantly determines weight gain, but the food we eat isn’t the only factor that plays a part. Additional factors to consider are:

  • Exercise – especially resistance training and heavy weights. Learn more
  • Sleep – proper sleep is essential for optimal hormone function, which impacts body composition
  • Stress – hormones released as a response to stress also negatively affect our bodies
  • Drugs – nicotine and caffeine often results in weight loss. Quitting smoking is clearly great If you want to gain weight, you might also want to switch to decaf

In this section, we’ll focus on non-exercise strategies to gain in a healthy manner.

What is the fastest way to gain weight?

untitled-6First of all, although wanting to gain weight fast is understandable, it subtracts from gaining weight in a healthy sustainable manner. Slow and steady wins the race.

Ultra-high calorie bulking diets are very common and do work very well for quick weight gain in some people. But usually, these people are extremely active bodybuilders/athletes who don’t mind gaining fat in addition to the muscle. With this kind of diet, people tend to load up on hundreds of extra grams of calories/carbohydrates per day and dramatically increase their protein intake. It works, and many people grow like weeds, but it usually comes with a varying amount of fat gain. And for some people this additional fat tissue can be difficult to lose.

There’s an even worse fast way: Eat ice cream and cookies constantly between meals, and wash it down with soda (in fact never drink anything other than soda). While this is highly likely to result in weight gain even for underweight people, you’ll gain mostly fat around your abdomen, making you “skinny fat”. That’s not a great look. Furthermore, it will increase your risk of type 2 diabetes and all kinds of health problems.

There’s a difference between gaining weight in the fastest way, and increasing in size in the healthiest way possible. The next few sections explain how we can progressively gain weight on a low-carb diet that is rich in healthy fats. The aim is to emphasize lean mass; in other words, maximize muscle gain and minimize additional fat.

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 first of all.

Nutrient density refers to how nutritious our foods are and the amount of beneficial proteins, vitamins and minerals present in them. There’s far too much focus on calorie counting and not enough focus on counting nutrients.

As an example, 500 calories from white rice and 500 calories from an avocado and a few eggs are entirely different. Yes, they have the same amount of energy, but the nutrients found in avocado and eggs completely destroy the minuscule amount of nutrients that white rice can offer. While rice provides lots of rapidly digested simple carbohydrates and not much else, an egg contains all the many nutrients needed to build lean body mass.

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 want to gain lean weight and find it hard, you should NOT do intermittent fasting. In fact you should aim to do the opposite. Eat often.

Try to eat at least every three hours, if possible even more often. Snack, but choose healthy options.

Here are some tips for what you could eat between meals.

Do sleep and stress affect weight gain?

Businessman with face pressed against wall, profile, close-upSince our muscles recover and grow during sleep, it’s essential to make sure we spend enough time asleep. In fact, sleep and stress share an intrinsic connection; if you are sleep-deprived, you are much more likely to be stressed. As a result, we want to avoid both of them.

It’s well-known that lack of sleep and stress raises cortisol levels. Unfortunately, higher cortisol levels have a negative impact on gaining weight in a healthy way. It may help you gain FAT mass, but at the same time reduce muscle mass (not good).

Higher cortisol levels both directly and indirectly influence weight gain (through overeating and the tendency to crave junk food).2

Cortisol is catabolic for muscle, the opposite of anabolic – in other words, it breaks down muscle tissue rather than building it.3 Consequently, to be in optimal condition and promote healthy weight gain, a few relatively simple things we can do include:

  • Sleeping 7-9 hours per night
  • Finding time to relax and enjoy our lives
  • Socializing rather than remaining isolated
  • Ensuring we don’t overtrain (exercise too much)


3. Healthy foods for weight gain


First of all, the cornerstones of a healthy diet should remain the same. Also, you want to be eating food that promotes health rather than diminishes it, so make sure to avoid all the common nutrition mistakes. The staple food groups of the diet should be based around:

  • Meat
  • Fish
  • Dairy
  • Eggs
  • Vegetables
  • Fruit (especially avocado, olives, berries)

However, among these nutritious food groups, we want to emphasize the most energy-dense of these foods to encourage weight gain.



Tender steak medallions topped with cheese on wooden boardsChoose fatty cuts of meat, preferably from pasture-raised animals. Red meat is one of the most nutrient dense foods, and it should play a prominent role in a weight gaining diet. Here are some good choices of meats:

  • Bacon (ideally traditionally cured)
  • Beef (ribs are particularly good)
  • Chicken (including skin)
  • Lamb
  • Pork (of all varieties – pork belly included)
  • Sausages (minimally processed, made with real meat)
  • Steak


Salmon fillet with fresh healthy herbs,vegetables, oil and spicesFor fish, we want to be eating the oily varieties. First of all, due to the extra fat, it is much more energy dense. Secondly, it is full of beneficial omega-3 fat. I recommend the following fish:

  • Anchovies
  • Mackerel
  • Salmon
  • Sardines
  • Trout

Not only are these fish the highest sources of omega-3, but they also have the lowest mercury content among commercial fish.


untitled-13Full-fat dairy is the way to go.

Despite the low-fat fad diet over the past few decades, the latest research shows how whole milk is so much better for you than the low-fat stuff. 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:

  • Butter
  • Cheese
  • Ghee
  • Greek Yogurt
  • Heavy Cream (Double Cream)
  • Whole Milk


French omelet with herbs, stuffed with mushrooms and onionsAll in all, eggs are one of the most nutrient-dense foods on Earth. As a result, they are your friend no matter what diet you are on.

Due to their high fat, protein, and micronutrient content they are perfect for weight gaining diets. 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:

  • Boiled eggs
  • Fried eggs
  • Omelets
  • Poached eggs
  • Scrambled eggs
  • Steamed eggs


Produce aisle in supermarket, close-upJust as with all the other food groups, nutrient density should be emphasized with vegetables too. As a result, we want to be eating lots of spinach, chives, garlic and mushrooms.

Any vegetable is a great addition, but you have a choice to make regarding starchy vegetables like potatoes, sweet potatoes, and other root vegetables. These tend to be higher in carbohydrate. Adding starches to a calorie-dense diet full of healthy fat will increase the speed of weight gain – a good thing. However, this will 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.

Learn more about low-carb vegetables


Fresh avocadoFruit can play a great role in a weight-gain diet. As well as being high in nutrients, avocados and olives are very energy-dense too, which makes them an excellent choice.

Another great food to include in the diet is berries. They can also combine with heavy cream to offer a delicious energy-dense snack/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 reasons to stay very low carb).

Learn more about low-carb fruits

Plant sources of fat

untitled-14There is a broad range of plant-based fats that you can add to the diet. These are relatively nutritious and also incredibly energy dense. Most noteworthy are the following options:

  • Avocado oil
  • Coconut oil
  • Dark chocolate (preferably 85% or above)
  • Nuts (almonds, cashews, macadamia, pecans walnuts, etc.)
  • Olive oil

Not only will these foods help you gain weight quickly, but they also provide you with several health benefits. Avocado, chocolate, nuts, and olives are all associated with significantly decreased cardiovascular risk in a range of large-scale studies.4


Coffee artUsually, I recommend against drinking calories. However, as this is a weight gain diet, consuming liquid calories can be useful. Some good, relatively healthy ideas include:

  • Glass of whole milk
  • Latte
  • Black tea/coffee with heavy cream
  • Cacao

Remember, this is about gaining weight the healthy way; that means no soda or sugary junk!

One thing you may be wondering is this; is it possible to gain quality weight on a low-carbohydrate diet? Don’t you need to eat carbohydrates? Let’s examine that now.



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

First of all, it’s a myth that building muscle and gaining weight isn’t possible on a low-carb diet. So, if you decide you want to gain weight while keeping the carbs low, that’s no problem at all. Many of you may know PD Mangan from Rogue Health and Fitness.

If you don’t know him, then he runs a website teaching men “how to be lean and muscular.” Also, he is 61 years young and has more muscle than most people in their twenties! As gaining weight the healthy way is his forte, I asked for his thoughts on building muscle on a low-carb diet.

Here’s what he had to say:

It’s an interesting area – bodybuilders swear by carbs, but research doesn’t back this up. For instance, insulin is necessary for muscle protein synthesis, but protein raises insulin as much as necessary, and adding carbs doesn’t mean increased synthesis of muscle.

Then there’s the issue of glycogen – since weightlifting is high intensity, a lot of the energy burned is glycogen – yet you don’t need a “full tank” of glycogen to get through a gym session, only a few hundred calories worth.

Another area is bulking – deliberately gaining weight. Unfortunately, bulking usually just makes people fat. So the advice I give to people who want to gain muscle is to ingest protein, at least 1.2 g/kg, and keep carbs low to moderate.

Evidence for weight gain with a low-carb diet

An interesting study from 2014 investigating the effects of a ketogenic diet on skeletal muscle.5 Particularly important is the fact that the study used a very low-carbohydrate intake (<5%). Additionally, the effect of this diet directly compared the effects of a traditional high-carbohydrate diet to the ketogenic diet. Twenty-six resistance-trained men participated in the study and were split into two groups:

  • 5% CHO, 75% Fat, 20% Protein (Ketogenic Diet)
  • 55% CHO, 25% Fat, 20% Protein (Traditional Western Diet)

After 11 weeks, the results were as follows:

  • The ketogenic diet resulted in a 2.1 kg greater lean body mass increase.
  • Fat mass decreased on the ketogenic diet by 2.2 kg (0.7 kg greater than the Western diet group).

To sum up, the results show that the very low-carb diet had more significant impact on lean body mass gain, weight loss, and body fat.

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 weight gain.

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.

If you have access to a gym, consider emphasizing “the big three” compound exercises; bench press, deadlifts, and squats. More than just about any other exercise, these three stimulate the most muscles fibers in your body. They’ll allow you to gain muscle faster.



5. How to overcome difficulty gaining weight?

In short, many people attempt to build muscle, fail and then conclude that it must be down to their genetics. While this may be true in rare cases, it’s usually because of a common mistake people make when trying to gain weight; not eating enough food. Adding more energy dense foods into the diet can quickly remedy this. Try adding an extra amount of these foods:

  • Avocado
  • Cheese
  • Coconut oil
  • Cream
  • Dark chocolate
  • Milk
  • Nuts
  • Olive oil
  • Yogurt

But, do take care to add additional amounts slowly, or you will just gain fat. Trial, monitor and adjust. And, if you still can’t gain weight?


15 quick weight-gain hacks

raspberryFinally, if you still can’t gain weight then here are fifteen ideas that I’m sure will help. Unless you’re in training to be a sumo wrestler, don’t implement all of them! 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.
  3. Add a protein shake to your 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 additional avocado each day.
  7. Add a few tablespoons of your favorite oil to your meal (coconut/olive oil are good).
  8. Sleep for longer than you have been doing; sleep is when you grow.
  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.

Final thoughts

All things considered, unlike the mainstream belief, gaining body mass doesn’t necessitate high carbohydrate intake. Looking at people like PD Mangan and Mark Sisson, both of whom are in their 60s, just goes to reinforce this point.

Sure; if you want to be a bodybuilder with a massive physique then consuming huge amounts of carbohydrate will get you there quicker, but that’s not what this article is about. A healthy diet full of 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.

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