How to Gain Weight with a Fast Metabolism: Expert Tips

how to gain weight with a fast metabolism

Gaining weight can involve eating a lot and – for most people – that’s a health concern.

Today we’re going through what it takes to gain weight safely (with a fast metabolism, especially). Gaining healthy weight isn’t a miracle – it’s actually simple once you understand it – so we’re going to cover how to do it, what to look out for, and the major factors that control your weight gain.

Ectomorph Body type: What does it Mean?

how to gain weight for fast metabolism

Ectomorph is a word we use to describe skinny guys – specifically ‘hardgainer’ types, who struggle with weight gain.

This isn’t a fatalist term. You’re not stuck being skinny forever, you’re just going to face different challenges to someone who – for example – has spent a lifetime being overweight. It’s a different set of challenges and priorities.

Ectomorph is how we describe a broad group of other factors like fast metabolism. But, crucially, it describes the outcome: being skinny and struggling to gain weight. 

 There’s no secret metabolic magic or genetic profile for being an ectomorph – so what are we really talking about?

What we really mean is a skinny guy who has a slighter frame. It’s an outcome, not a set of symptoms and not a mechanism. You don’t need to blame being an ectomorph when the only causes are within your control – you just need to know how to gain weight with a fast metabolism.

This all starts with the main misgiving of ‘ectomorph hardgainers’…

How to Gain Weight with a Fast Metabolism

In order to gain healthy weight if you have a fast metabolism, you need to consistently stay in a calorie surplus while indulging in a resistance training sessions and getting adequate sleep. The extra calories you consume is going to help you gain weight, while the training and recovery part will ensure that most of the muscle you gain is in the form of lean muscle and not unhealthy fat.

What is Healthy Weight Gain?

gain weight fast

Before we even start, it’s important to understand that weight gain is not unhealthy or unsafe by itself. How to gain weight naturally? Appropriate diet and exercise!

You can gain weight fast in an unhealthy and reckless way, but that’s not because the number on the scale went up. Weight and health are only associated – if you’re gaining muscle, eating a healthy balanced diet, and being patient then you can gain weight healthily.

The health problems of weight gain come when they’re associated with things like obesity, diabetes, and nutrient deficiency in some people’s diets (1). If your weight-gain is built around a deliberate strength training routine and based on nutrient-dense foods, your weight gain will be healthy.

While the body does respond well to regular periods of calorie restriction, that doesn’t make weight gain unhealthy. Use all the same priorities you would with weight loss – like eating your vegetables and high-quality proteins – and you’ll stay healthy while building muscle.

Eating relative to your own needs

This is the important truth: ectomorphs are not excluded from the normal way that weight gain works. There are easy ways to gain weight.

Ectomorphs and hardgainers just haven’t remembered one of the key lessons: weight gain happens relative to individual need. You can’t just eat “a lot of food” relative to someone else’s physical needs and be confused when you’re not gaining healthy weight.

It’s important to adjust weight gain to your own calorie needs and ensure that your calorie surplus is about you. It doesn’t matter how other people gain weight – you need to re-balance the numbers to gain weight with a high metabolism.

Ultimately, the only way to tell if you’re eating enough is to watch changes in the data: your bodyweight and your lifts in the gym. These two factors will provide the only objective measure of whether or not you’re eating enough.

Your body’s needs come first and addressing these – eating enough to move the scale (roughly 0.5lbs per week in muscle gain) is the key. Finding the number of calories required is the first step to gaining healthy weight.

This is where a lot of hardgainers go wrong when asking themselves how to gain weight fast – stop concentrating on how much other people think is a lot of food.

Nutrition: Eating to Gain Weight

gaining weight with fast metabolism

You cannot gain weight without appropriate nutrition. It’s the driving force behind any gains you make – both in muscle and fat. The changes you’re looking for require an abundance of energy in the diet and that’s about how much you’re eating relative to your needs and activity levels. 

Step One: Calories for Weight Gain

Calories measure energy in food. Eating more energy than you use forces you to store it (2). The surplus is either used to build more muscle or stored as fat (depending on how much you’re eating and what your lifestyle is like).

Even when we ignore health or protein or any other factor, calories have to be right (they are the best way to gain weight).

You have a TDEE – a rough average of your energy requirements. When you eat over this, your body is going to gain weight as energy is used or stored. This requires eating more, whatever your personal needs are.

Track your calorie intake. It’s useless worrying about gaining weight if you’re not actually measuring your intake – you need to produce consistent eating over TDEE and that only works if you know what it is and what you’re eating!

Sometimes the TDEE will be off, and you’ll need to adjust. It’s important to have this starting point and you can add calories over time if you’re not successfully gaining weight. Having a point to work from is a huge bonus and provides you with a goal for deliberate, measured eating.

Step two: Macronutrients – Protein, Carbs, and Fatshow to gain weight naturally

Macronutrients cover the 3 most common, most in-demand nutrients from food. These are Protein, Carbohydrates, and Fats.

These make up the vast majority of calorie-sources in your diet and have unique characteristics. We’re not getting into them today, but it’s important to understand the role they play in weight gain (and to find out the best way to gain weight).

Protein is the general building-block material of most of your body’s structures (3). It goes into everything from muscle to tendon to bone. You need to eat protein to build new tissues which, of course, includes building muscle mass after exercise.

Protein intake should be roughly 1.5g per kilogram of bodyweight. This is a good starting point, along with TDEE, to structure your diet around. More is usually better, too, as long as it’s not eating into your carb or fat requirements for the day.

Carbs are the short-term energy source your body needs, and they come from a wide range of sugary and starchy foods. Everything from bread to oats to potatoes. Carbs are required for energy abundance – the driving force behind both muscle-gain and fat storage.

Carbs are the best place to get most of your calories on a weight gain diet, usually around 4-6g per kilogram of bodyweight. This helps support the energy-expensive processes of weight gain, driving the muscle-protein synthesis pathways that respond to exercise by building more, stronger mass.

Dietary fats are a slow-burning energy source. They’re primarily involved in the diet as a catalyst for fat-soluble vitamins and improving/regulating hormonal health.

Fats are high in calories but can be digestively demanding, filling, or easily over-consumed. 

You should prioritize high-quality (preferably unsaturated) fats like olive or coconut oil as a way of boosting calorie intake and supporting hormonal wellbeing, thus helping you gain weight safely. They’re likely to take up around 15% of total calories but shouldn’t be the main focus.

TIP: A great way to get high quality calories in is to take homemade weight gain smoothies throughout the day.

Step three: Micronutrients – Vitamins and Mineralsways to gain weight

Micronutrients are the difference between gaining healthy weight or unhealthy weight for most people.

These are the health-promoting compounds found in conventionally healthy foods like fruit and vegetables. They support bodily processes, ensure everything’s running smoothly, and keep your systems (e.g. metabolism) efficient.

Any diet – for weight loss or gain – should focus on getting plenty of micronutrients. Whether gaining or losing weight, the goal should be to maintain sufficient (if not optimal) levels of nutrient intake.

This is why you still need to focus on food source and quality. A wide variety of plant-based food sources, wholegrains, veg, and high-quality protein sources (like eggs, seafood, and beans) provide plenty of micronutrients.

It’s important to focus on these at a priority (regardless of calorie content) before adding higher-calorie foods afterwards. Nutrient deficiency is a significant health problem and should be avoided wherever possible. Whether you’re getting shredded or jacked, you need to eat your veggies.

You could also go for some weight gain supplements that help you gain weight safely while also ensuring you meet your health needs.

Training: Turning Calories into Muscle Mass

If you are trying to find out how to gain weight with a high metabolism, exercise and activity levels are a significant factor in your bodily change.

They impose demands on the body. These determine what your body does with things like food and rest, what changes they produce, and even the number of calories you need.

For example, doing huge amounts of endurance exercise changes how much you need to eat. If you’re running marathons every day, you’ll need 1000s of extra calories per day to get into a calorie surplus compared to a regular fitness enthusiast or sedentary office worker.

This is how we ensure that weight gain is high-quality. The training stress of things like weight training, gymnastic strength training, and sport/activity ensure that weight gained is muscle, tendon, and bone density. These are the benefits of exercise and underlie an effective weight-gain.

Effective, safe, healthy and the best way to gain weight is a 3 step process:

  • 1) Training that provides lots of volume (measured as weight * total reps) 
  • 2) Progression of volume from workout to workout or week to week
  • 3) The patience to slowly build up more work capacity over time without getting injured
  • Safe weight gain relies on a healthy amount of exercise relative to the resources you’re putting into your body. Healthy activity levels are important by themselves, too – you can’t eat and sleep yourself out of everything

    Sometimes, you need to adjust for rest…

    Rest & Recovery: Where Results Really Happenhow to gain weight fast

    Sleep Your Way to Muscle Gain

    Sleep is only second to nutrition. It’s maximum recovery time and it offers the most potent effects to your physical progress, change, and wellbeing.

    Sleep directly controls things like the health of your most important hormones. When you sleep effectively, you’re giving your body the specific, deliberate recovery time it requires and has evolved for (4).

    When you’re sleep deprived or in sleep debt, you’re going to rapidly deteriorate. The body and mind are both dependent on sleep and when we lose an hour a night, changes occur rapidly at the hormonal and psychological level.

    The muscles themselves are also slower to repair and experience less growth, as well as a loss of neuromuscular power (the ability to produce force rapidly). These impact not only the way you perform but also the way you feel and the amount of progress you can make from session to session.

    Prioritizing sleep will make literally every aspect of your life better. 1 hour of high-quality sleep can spread significant benefits across all of your waking hours. 

    Rest Days Make You Bigger and Strongerhow to gain weight with a high metabolism

    Even the best recovery systems in the world – a perfect supervised diet, amazing sleep, and the world’s best workouts – are useless if you’re not resting enough.

    A lot of hardgainers want to work out every day to pack on mass. In fact, the opposite is true – a few great workouts with high-quality rest days is the fastest way to pack on high-quality muscle mass. More time recovering means more muscle protein synthesis, more neuromuscular recovery, and not piling up extra calorie-burn.

    When you replace a rest day with a workout you’re placing extra stress on your body without the downtime necessary to make it work. Remember: you get better when you rest, not when you train.

    Downtime and Relaxation: De-Stress for Weight Gain

    The science of performance is starting to tell us – more and more every decade – that your mental recovery and mind-state are tied into your physical recovery and performance.

    The stressors on your mind and body contribute to an overall system of stress. When you’re stressed mentally, you’re sending signals that disrupt the recovery stimulus. Your body and mind recover effectively when you’re tapped into your parasympathetic nervous system – dedicated to rest, recovery, and digestion.

    When you’re stressed, on the other hand, you’re activating the sympathetic – fight or flight – system. These are at odds, and the way that you control your stress and anxiety levels in life will show up in the results that you get from exercise.

    Weight gain is both easier and higher-quality when you’re destressed. This means a few things. First, it means you should try and minimize the stressors in your life wherever possible to support a better everyday recovery process.

    Second, it means that the way that you handle your stress and anxiety has a direct bearing on your results from the gym and your diet. When you’re more able to handle stress, you reduce the possible negative impacts they have on your lifestyle.

    The things you do matter across both the physical and psychological fields. Your ability to manage these relies on both your personality (and mental health and robustness) but also daily habits. Making time for reflection, deliberate relaxation and calm, and even simple de-stressing habits like regular reading and teas (such as chamomile and valerian) can help manage anxiety.


    How much weight can I gain safely?

    It depends entirely on the timeframe. You can gain huge amounts of weight healthily if you’re patient and work at it over the span of years or a decade. 

    The faster you gain weight, the less healthy the process is likely to be. Focus on building reliable, healthy weight-gain habits and your weight will change as quickly as it is healthy to do so. If you let patience and good habits lead the way, you’re going to be gaining healthy weight.

    How quickly should I gain weight?

    It depends on your existing weight, height, and frame. Usually, we recommend .5lbs or roughly .25kg per week.

    This is around 500 calories of surplus everyday per week, which can obviously be averaged out differently through the week. The idea is that too many calories will just promote excess fat, while too few will limit your ability to train hard and progress with strength training (e.g.).

    This obviously shifts up or down with your personal needs. For small, lighter women this number may be lower (around 200-300), while for very tall, heavy men it could be higher (800ish). This is why it’s important to adjust based on the results you see in the gym and on the scale.

    What sort of foods should I eat to gain weight?

    You should eat high-calorie, nutrient-dense foods. Especially those rich in protein and carbohydrates.

    We’ve written a whole article on the best weight gain foods, but the short version is this: eat high-quality foods that are rich in calories. Fatty fish, eggs, cultured dairy, wholegrains, nuts and seeds, beans and pulses.

    Your diet should be abundant in energy (calories) but also the important fuels for health and wellbeing. The best weight-gain diet only uses luxury high-calorie foods (like ice cream) when it fits into a multi-ingredient meal or after a day of eating high-quality, healthy foods.

    When should I stop gaining weight?

    Whenever you’re either satisfied with hitting your goals or feel like you’ve gained excess body fat.

    These are the two main reasons to stop gaining weight and reassess your goals. Either you’ve hit your goals and need a change of pace, or your process needs reviewing to get you back on track.

    Have a review at set intervals – maybe every 2-3kg of bodyweight gained – to make sure you’re doing the right thing for you. Goals change and evolve over time and weight gain can be a stubborn process.

    Can I eat “unhealthy” foods on a weight gain diet?

    The answer is probably yes, as long as the overall diet is good.

    If you’re excited to up your calories so you can fit in that big salty burger and cheesy fries, that’s fine. Just make sure your weight-gain diet doesn’t exclusively consist of foods that you know you shouldn’t be prioritising.

    These kinds of luxury foods are a great benefit for a weight gain diet where you have the calories to really enjoy them. Just remember that they should be surrounded with healthier foods that are serving your body’s basic needs.

    The key to dieting for weight loss and gain is the same: they’re only a problem when it’s a pattern of behavior. One dirty meal is a great time, 2 a day everyday might be undermining your health when gaining weight.


    Gaining healthy weight can be a safe, rewarding process that both improves your wellbeing and ensures that you’re making the best of your exercise. 

    It can drive your strength, athleticism, and physique change. It does, however, rely on getting nutrition and rest right – as well as training. Gaining weight safely relies on the choice of high-quality foods, a focus on balance, and staying relative to your needs.

    How to gain weight with a fast metabolism safely? Focus on the basics. Train, recover, repeat – weight gain is going to happen. But when we focus on the finer details like food quality, micronutrient density, and proper rest/relaxation, weight gain can be an immensely healthy, safe process.

    Weight gain will almost always be healthy when it is patient and focuses on good habits.

    Focus on making changes to the things you do every day – your sleep habits, your food choices, and how you manage your stress. Patience and consistency here will highlight the small, day by day changes that drive both health and building muscle mass!

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