Why Can’t I Gain Weight Despite Eating More?

why can't I gain weight

Hardgainers and ectomorphs are guys who constantly ask, “why can't I gain weight?”

It’s a common problem because weight gain is slow and stubborn.

The good news is that there’s nothing wrong with you if you’re a hardgainer: you can gain high-quality weight, you just need to make sure you’re not falling into these 6 weight-gain traps and keep your eye on the 6 most common reasons you’re not gaining weight

We’re going to explain what you can do about it. By the end of this article you’ll be ready to beat the stubborn weight plateau and make real gains.

Ectomorph Bodytype: Why Am I Not Gaining Weight?

not gaining weight

The ectomorph body type is a term we use to refer to a certain type of build or person. It usually refers to a thin or “skinnyfat” physique and someone who cannot seem to gain quality weight or muscle.

When we say ectomorph we usually mean: 

  • Fast metabolism: a higher resting metabolic rate is usually seen in younger guys. This can be during the teen years, for example, when the metabolism is naturally higher to account for the changes of puberty and its demand on energy for growth (1).
  • Low appetite: a lower appetite can make weight-gain difficult and lead a person to eat a relatively small amount of calories across a day. This will naturally lead to a smaller, slighter physique over time.
  • High NEAT: working high-activity jobs and other forms of daily non-exercise activity can burn more calories than you think. NEAT – non-exercise activity thermogenesis – can account for up to 50% of daily calorie-burn and up to 2000 calories a day. An easy way to stay small.
  • Miscounting food: why am I not gaining muscle? Because many hardgainers just aren’t tracking effectively. We suck at reporting our food effectively and may misjudge portions. Misunderstanding the calorie content of foods – especially unhealthy foods – can obscure just how little someone is eating!
  • Narrow frame: a narrower set of shoulders and slighter frame is one of the keys to being an ‘ectomorph’. You can’t change bone structure, but most guys aren’t going to be limited by their bone structure – but rather by the amount of muscle mass across the chest, shoulders, and traps.

The main point is that these are smaller people of slighter build. This doesn’t directly stop weight gain, however, and struggling to gain weight is about behaviors. It can be frustrating to feel like you’re eating but not gaining weight.

The reality is that hardgainers are just struggling to get the right balance. Weight gain is slower than weight loss and requires just as much discipline, as well as a lot more training

Here’s the key fact: nothing is stopping you from gaining weight. You are in complete control of the systems that change your bodyweight – meaning that you’ve got to take responsibility for them and pay more attention to them. 

Often, it’s just set up with a slightly different balance – a fast metabolism, a high turnover of calories every day, or just being too full to reach the appropriate calorie needs for the day.

Medical Reasons for Not Gaining Weight

gain weight safely

Some people aren’t just under-eating but have real medical issues behind their weight. These are not ectomorphs or hard-gainers and they’re not the target for this article.

Real medical considerations for being underweight may require medical attention – either physical or mental. If you’re experiencing other effects or unwanted weight loss, contact your physician or other qualified medical professional.

Medical conditions can occur at the hormonal, metabolic, and digestive levels. Conditions affecting the absorption of nutrients in the gut or the body’s ability to produce things like muscle proteins. These are serious issues that need proper testing and diagnosis – not just more food.

If you’re doing everything else right – tracking, eating, training, and you’re struggling to maintain or gain weight – then it’s worth talking to a dietitian. We all have different needs and there are real medical reasons for not gaining weight.

However, for most hardgainers and ectomorphs out there, there are 6 non-medical reasons for not gaining weight…

Top 6 Mistakes Hardgainers Make

Improper Expectations of Weight Gain

how to gain weight

Most people have incorrect expectations about how much they can gain in a given time.

It’s easy to think you’re a hardgainer if you’re not aware that the human body is unlikely to build more than a pound of muscle every two weeks (2). Beginners often expect faster results – especially with the background of fitness industry hyperbole.

It’s easy to think you’re a hardgainer if you don’t realize how hard weight-gain can be for everyone. Commit to the process and be patient.

Worrying About Other People’s Standards

Worrying about how much you eat relative to your friends, girlfriend, mother, or other athletes is an easy route to failing on your dietary goals.

Your diet needs to reflect your needs and it doesn’t matter what anyone else thinks about those amounts of food. People who have no experience with nutrition may think you’re eating a lot and it may be affecting your perception of how much you eat.

Tracking and a personalized diet allow you to focus on these needs and produce results. If you’re a hardgainer relative to a small woman, for example, you’re probably not a hardgainer or ectomorph.

You’re just normal and need to adjust your perspective on what “eating a lot” is.

Eating Badly but Low-Calorie

eating a lot but not gaining weight

Eating unhealthy foods is not the same as eating lots.

Many hardgainers and ectomorphs are just eating badly and treating it like eating tons of food. Spending every lunchtime at your local McDonalds is not the same as eating lots of high-quality weight gain foods.

These foods are not as calorie-dense as many people suspect and can easily lead to overestimating calorie intake. Just because they’re associated with weight gain, it doesn’t mean they’re directly causing it.

Eating instant ramen won’t make you fat – it’s just not very nutrient-rich. This kind of eating is super common in “hardgainers” where it’s mistaken for eating lots. Tracking calories will help you untangle your expectations around certain foods and their contribution to helping you gain weight.

Being Scared of ‘Unhealthy’ Foods 

Gaining weight is hard if you’re insisting on the purity and lean-ness of all your foods.

Conventional health foods tend to be lower in calories and make a poor calorie source for gaining weight. Ditch chicken breast for something fattier like lamb, lean into higher-calorie carb sources, and don’t worry if you add 500-1000 calories of cheesy potatoes here and there.

Getting too stuck into the health of a weight gain diet is going to leave you with a foot in either camp, and another reason for not gaining weight. Weight gain isn’t unhealthy when it’s muscle mass from a well-balanced diet: luxury foods aren’t just going to make you unhealthy.

Eat healthy foods to get your nutrients, then feel free to eat that cake at the end of the day.

Not Tracking Macronutrients for Muscle Gain

counting calories

If you’re not tracking your calorie intake and macros, you don’t know if you’re eating enough.

More food almost always means more weight gain but getting the sweet-spot for your needs is more subtle. If you are eating a lot but not gaining weight, tracking helps you in a few ways.

First, it helps you make sure you’re getting the right amount of calories and macros. This is the obvious benefit – if you’re not tracking, you don’t know if you’re in the right range or not.

Second, it helps you better-understand the real calorie and macro content of foods. This is part of the education process that helps you control your diet and expand your control over your own body. 

Finally, it’s a great way of staying accountable to yourself. Knowing that the numbers are wrong, and you need to eat more will help you get into the habit of eating more over time.

Not Adjusting Your Needs as You Gain Weight

One of the biggest mistakes is not adjusting your calorie needs upwards while gaining weight.

It’s easy to forget that your body is changing and needs different things over time. Eventually, eating more calories will increase your mass and your “weight gain diet” will turn into maintenance.

It’s important to update and adjust your TDEE in line with your gains to make sure you keep progressing. It sounds obvious but these calories can sneak up on you and suddenly you’re stalling on your bodyweight.

Update every 4 weeks or every 2kg of bodyweight. It’s a small change that adds up over time.

6 Reasons you are not gaining weight

 If possible, divide the section into Medical Reasons & Lifestyle Reasons, but if not just add as sub headings all together Examples: 

You Are Not Eating Enough

eating but not gaining weight

This is the simple reality. You need to eat more.

No matter why you’re a hardgainer or struggling to eat enough, the solution is the same. Eat more.

The whole point is that your energy balance is not where it needs to be in order to build more muscle mass and long-term weight gain. Consistent under-eating is the only reason that healthy people (i.e. those without serious medical conditions) can’t gain weight.

If you’re eating and your body is digesting it, then the only difference between weight loss, maintenance, and gain is the amount. There is no way to eat more than you burn and not gain weight – as a healthy person.

If you’re not gaining weight – either due to undereating or extremely high activity levels – the solution is the same: eat more.

You Have a Fast Metabolism

why am i eating and not gaining weight

First thing is first: having a fast metabolism does not mean you can’t gain weight.

You just have to try harder.

When you have a “fast” metabolism, you’re just setting a higher daily calorie maintenance level. This is your personal requirement just to stay at the same bodyweight. When your TDEE is higher, you have to eat more than someone with a slower metabolism, and especially when you’re trying to gain weight.

Faster metabolisms just shift everything up. This is why we work from your TDEE up: your individual needs should inform your intake. Use your own TDEE and adjust 500 calories up, you just need to start with the assumption of your fast metabolism.

 A fast metabolism isn’t going to limit weight gain if you account for it. It’s just another way of getting more nutrients into your diet as you’re eating more food. Be prepared to eat more often and more calorie-rich foods (even the “unhealthy” ones).

You Are Not Consistent with Diet or Workout 

Consistency is a key factor. Your body doesn’t gain quality weight quickly, so one day of eating huge amounts of food isn’t going to make a long-term difference.

What matters most are the daily and weekly averages of calorie intake. These reflect the consistent eating that it takes to build muscle and gain weight slowly and steadily. Your body doesn’t have any alternative to slow and steady weight-progress, so you need to learn to be patient.

It’s also important to work on persistence: when setting out weight-gain goals you should be looking at months or years into the future. It will be a significant amount of time to turn effort into weight and the best approach is one that acknowledges and embraces this patience.

Ironically, the best way to gain weight is to spend very little effort worrying about gaining weight. There are only 2 things you really need to do to gain weight effectively in the long-term:

  1. Eat more calories, on average, than you use 
  2. Focus on the daily habits of training, nutrition, and recovery

The more you spend on part 2, the better your results will be. This will drive all the best benefits of exercise and weight-gain, while your weight lags behind (3). Your body is responding to demand, and it takes a while. Plan a lifestyle and habits that you can sustain now, in a month, and in a year.

If you’re committing to less time than this, you’re liable to trip over your own expectations. You’re in this for the long-run, get comfortable working on the quality of your training and lifestyle!

You Are Eating Only a Little Over Your Maintenance Calories 

This is a common one – you’re eating over your maintenance but only slightly.

It’s normal to be worried about gaining fat when you’re on a weight-gain diet. Many people will stick to only 200-300 calories over maintenance to try and avoid gaining unwanted fat but will undermine their efforts to get bigger and stronger.

These are the results of an effective weight-gain diet. We always recommend starting around 500 calories above maintenance to ensure that you’re both facilitating recovery from high-intensity exercise and making sure you have enough resources to build additional muscle mass.

Energy abundance is the key to driving positive adaptation after exercise. When you’re only eating 250 calories over maintenance, it is likely to take you around 4 weeks to gain 1lb of muscle mass, while 500 calories would halve the time.

Remember that your surplus calories are the key to your muscle gains. If you’re really dealing with stubborn weight gain, you may need to go up to 800 calories above TDEE, especially if the scales are stalling out after a period of consistent gains or changing your workout plan.

Remember to adjust your calorie-intake regularly to reflect changes to things like muscle mass, activity levels, and overall workout volume. As you get bigger and stronger, your TDEE is only likely to go up and you may need to account for that with more calories above maintenance.

These are the only calories that actually make you gain weight. Commit to them and eat more.

You Are Focusing on Low Calorie Foods

weight gain foods

Many people fail their weight-gain goals because their attention is stuck on low-calorie foods. This is common for a lot of health enthusiasts who are uncomfortable working with “unhealthy foods”.

It’s easy to be a ‘hardgainer’ if you’re constantly eating nothing but vegetables. These kinds of foods have high volume relative to their calorie intake: they take up a lot of space in your digestive system while providing very few calories.

For weight-loss dieting this would be perfect. However, when you’re on a high-calorie diet, you need to balance up your calorie and nutrient intake with the amount of satiety that a food provides.

Too filling will result in you being unable to eat more food for long periods of time when you still need more calories to reach your daily goals.

Foods like vegetables are great. They provide nutrients and support digestive health. However, sometimes this enthusiasm needs to be directed towards higher-calorie vegetables and plant foods: avocado, olives, wholegrains, nuts, seeds, beans, and pulses.

Classic veggies are popular because of the need for calorie-restricted weight loss diets.

However, shifting focus to weight-gain friendly vegetables provide all the same important nutrients without the serious challenge of getting enough calories into your diet. Remember that vegetable choice, like other aspects of diet, are personal and need to be justified by your goals

Don’t get caught up eating celery just because you think it’s a good food. Higher-calorie alternatives suit your diet better.

How to Gain Weight Safely

why am i not gaining weight

Gaining weight is a simple but demanding process and – often – requires you to be stubborn. 

If you think you are eating a lot but not gaining weight, you’re going to need more calories than you’re burning which often means eating near-uncomfortable levels of food. It can demand calorie-dense foods, unusually regular meals, and adding high calorie shakes to reach the calories you need.

This also means prioritizing proteins and carbs – especially together. These are the top priority for your meal-construction, every meal should be rich in both

Protein should be around 1.5g per kilo of bodyweight, with carbs at 2-4 times as many. Fats are there to add extra calories, as high-quality fatty vegetables, and other sources like yoghurt, peanut butter, or cheese.

Carbs should primarily be starches and – again – from high-quality sources. Beans, potatoes (and sweet potatoes), rice, and other staples. These boost your energy-storing response and support the uptake of proteins when eaten together and offer a great balance of hunger-satisfaction and calorie-density.

After your protein and carbs, it’s simple: more vitamins and minerals. Select nutrient-rich foods like fruit and veg, or nuts and seeds, to support your health and wellbeing.

When you pair these nutritional habits with regular, heavy strength training you’re going to gain high-quality muscle mass. With a clear focus on quality rest and sleep habits, weight gain is both guaranteed and high-quality, turning your efforts into results and helping you gain weight consistently.

Conclusion: 12 Reasons You’re Not Gaining Weight?


There are a wide range of things you could be getting wrong that result in stagnating bodyweight. Even if you think about eating but not gaining weight, the solution to "why can't I gain weight" is to eat more.

There are many steps where you could get your estimates wrong for either calorie content, portion size, your own calorie needs, or just what “a lot of food” is! Just because you eat more than the people around you, it isn’t always the case that you’re eating more than your body needs.

If you are eating a lot but not gaining weight, stay focused on your own needs, intake, and what the scale is telling you. It’s only a lot of food if it makes the needle move on the scale and fuels your weight gain.

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