Gain 10lbs with a fast metabolism

How To Gain 10lbs With A Fast Metabolism: What Skinny Guys Should Know About Bulking Successfully

A skinny person often feels like no matter how much they eat, their sky-high metabolism prevents them from packing on any significant mass. This post explains how to gain 10lbs with a fast metabolism.

Skinny people can gain 10lbs (5kg) with a fast metabolism by increasing nutrient intake and performing resistance training. 10% surplus calories and a protein intake of 1g per pound of body weight should be consumed daily. Weight training should be intense and focused on progressive overload.

5 years ago, I was the average skinny dude on the block.

No matter how much I trained or how much I thought I was eating, the scales just would not budge.

But through extensive research and a lot of trial and error, I managed to overcome my genetic cursing.

Below, I reveal why you may not be as doomed to a scrawny frame as you think you may be.

Yup, there’s a way around it!

You can keep reading to find out my tried-and-tested tips.

How I gained 10lbs (5kg) body weight as a skinny guy with a fast metabolism.

Products Mentioned In This Post

There’s a big difference between putting on 10lbs of weight (fat and/or muscle) and 10lbs of healthy muscle weight.

If you’re interested, here’s the home gym setup I used to out on 10lbs of muscle weight at home!

How To Gain 10lbs Weight On A Fast Metabolism

It was only until I sat down to count every single calorie I was consuming, that I realized there was a fundamental flaw in my weight gain program:

What I thought was a 2700 calorie daily intake turned out to be just 2000 calories!

As such I wasn’t feeding my body with the energy it required to build muscle and gain weight.

Consequently, I wasn’t able to increase the weights I was lifting either.

Ultimately, my inability to gain 10lbs (5kg) wasn’t just because I had a high metabolism.

But it was mainly because I wasn’t eating enough!

But don’t just take my word for it.

I also tracked down this Reddit thread which asked:

“How do skinny people gain weight fast on a high metabolism”.

I compiled all the responses and you can see the results below.

How Reddit uses gain weight fast on a high metabolism.

Here’s what Redditors feel to be most important for you to gain 10lbs on a fast metabolism:

  • 87% of people agreed that increasing food intake is the most important aspect.
  • 58% of people agreed that eating more meals with calorie-dense ingredients is also important.
  • 17% of people agreed that calorie counting to hit nutriton targets is key.
  • 13% of people agreed that heavy weight training is essential.

Simply put- you should eat big and lift big to get big.

By consuming more calories than you burn (aka a calorie surplus), those extra calories will go towards increasing your body weight.

And when you combine a calorie surplus with heavy resistance training, you’ll make sure as much weight as possible is coming from muscle and not just excess fat.

How To Eat To Gain 10lbs On A Fast Metabolism

Skinny people with a fast metabolism should eat at least 10% daily surplus calories to gain weight. Furthermore, calories should come from a macronutrient profile of approximately 25% protein, 50% carbohydrates, and 25% fats. This provides the essential nutrients to build muscle and gain weight.

The process of eating surplus calories for extended periods to build muscle is called bulking.

And bulking is the bread and butter for those looking to gain 10lbs of weight on a fast metabolism.

“Bulking requires a combination of eating more calories, a good macronutrient balance, good nutrition, and adequate strength training.”

Emmie Satrazemis, CSSD, Trifecta Nutrition.

Calculating your 10% surplus calories requires you to first determine your maintenance calories.

These are the minimum calories required to fuel your daily activities and maintain your weight.

The quickest way to determine your maintenance calories is by plugging your metabolic details on TDEE.

Now you can add a 10% surplus.

For example: if a 140lb male needs 2500 maintenance calories every day to keep their current body weight, then a 10% surplus would mean he would need to eat 2750 calories per day to gain a healthy weight (2500 x 1.10).

These extra calories are used to increase body weight either through muscle gain or stored fat.

Additionally- if you’re weight training on a bulk (to increase muscle size and weight), then a high protein intake is also key.

You’ll need at least 1g of protein per pound of body weight.

For example: a 140lbs skinny male/female would need at least 140g of protein a day.

A 10% calorie surplus, high protein intake, and intense weight training are sufficient for a skinny person with a high metabolism to gain 10lbs (5kg), mostly through muscle weight.

How To Eat Macronutrients To Gain 10lbs On A Fast Metabolism

Calorie and macronutrient targets should be spread over at least 4 main meals per day to effectively gain 10lbs (5kg) on a fast metabolism. 2 large snacks should also be consumed in between meals. This typically requires the person to eat at least once every 2 to 3 hours.

How to Gain Weight Fast for Skinny Guys

You can also check out Joe Frazer’s tips on bulking up as a skinny hard gainer with a high metabolism!

Therefore meal timing – as well as reaching overall calories and macronutrients target- is key to gaining 10 pounds on a high metabolism.

Frequent meal times yield the best results.


A higher meal frequency lessens the effects of the bloated feeling you get after consuming a heavy meal.

This constant “full-feeling” is a common issue that many skinny beginners have when bulking.

But if you eat a higher number of meals throughout the day, with few calories per meal, this helps a lot with reducing the uncomfortable bloated feeling.

Each meal should have a balanced source of macronutrients, as follows:

MacronutrientTypical Percentage Calories Per MealWhy It’s Important
Protein25%Supplies amino acids which are the building blocks for muscle growth.
Carbohydrates50%Supplies energy for workouts, fuels the muscle-growth process, and contributes to post-workout glycogen replenishment and recovery.
Fats25%Calorie-dense macronutrient that supplies energy for weight gain and muscle-building.

Meal Timing: Pro Tips

Here are meal timing tips that helped me to gain 10lbs (5kg) weight on a high metabolism:

  • Breakfast is key. This is one of the most important main meals, and also one that many skinny beginners struggle to eat enough calories on. Breakfast is a period where your body is exiting from a fasted state. Consuming a high calorie breakfast kickstarts your metabolism and can also help to stimulate your appetite throughout the day. I like to make a calorie-packed smoothie which is easy to consume (see below).
  • Make 2 of your meals a pre-workout, post-workout. These are the periods where your body will most readily burn off your calories. So desginating a significant portion of calories to these times will help reduce feelings of bloatedness throughout the day. Aim for a mixture of high protein, healthy fats, slow-digesting (e.g. pasta), and quick-digesting carbs (e.g. banana).
  • Make 1 of your meals a pre-bed meal. Most of your body repair and muscle regeneration processes happen during deep sleep. So it’s good to keep your body topped up with energy overnight to fuel weight gain. Designating a high amount of calories to a pre-bed meal can also mean you feel less bloated during the day when you are working and generally need to be more active. Try to opt for slow-digesting complex carbs rather then simple sugars.
  • Spread your protein intake evenly thoughout the day. Your body can only absorb around 25g of protein per meal. The rest ends up in the toilet. So smaller protein portions consumed more frequently is much better than jamming all your protein into a few meals.

You may also be interested in my other post to find out how hard it is to gain 10lbs (5kg) as a skinny person.

What To Eat To Gain 10lbs On A Fast Metabolism

Calorie-dense foods are ideal to gain 10lbs (5kg) of weight on a fast metabolism. Examples include fruits, sugary foods, whole grains, fatty meats, vegetable oils, nuts, and seeds. These ingredients have a low serving volume but contain a high amount of calories.

Here are some of my favorite nutrient-rich food recommendations:

Foods To Gain Weight On A Fast MetabolismTypical Calories Per 100gTypical Protein Per 100g
Grains (pasta, oats, bread, rice)36012g
Peanut and almond butter60025g
Sweet fruits1000g
Fatty cuts of meat20020g+
Oily fish21020
Olive oil8800g
Nuts and seeds58021g
Cow’s milk (100ml)453g
Coconut milk2302g
Full-fat cream3802g
Whey protein powders15025g
Weight gainer powders100050g
Prioritize unsaturated healthy fats over saturated unhealthy fats when trying to gain 10lbs (5kg).

1) Unsaturated vs Saturated Fats

If you’re trying to gain weight fast on a high metabolism, you should prioritize fats over carbs.

That’s because fats have more than double the calorie content compared to carbs (9 calories vs 4 calories per gram).

So you’re getting more calories for less stomach space.

Additionally, you should also choose the right types of fat.

Naturally healthy fat variants include the unsaturated fats found in nuts, seeds, vegetable oils, omega-3-rich oily fish.

Not only are these good for bulking on a high metabolism, but they’re also beneficial for controlling cholesterol and maintaining heart health.

In comparison, unhealthy saturated fats are found in processed meats, junk food, confectionery, and fatty meats. And these are generally bad for your health.

With that said, unsaturated fats can still help you to gain 10lbs on a fast metabolism though, just eat them in moderation.

Blend protein powders with fruits, honey, peanut butter, and oats for a homemade weight gainer shake.

2) Protein Shakes

Liquid calories can also be great for gaining 10lbs (5kg) on a fast metabolism.

These are simply calorie-rich shakes and smoothies which deliver fast-digesting nutrients.

This means the feelings of “fullness” after a shake are much shorter-lived, compared to eating a steak and potato dinner for example.

Try blending protein powders with fruits, beans, ice cream, milk, olive oil, and oats.

They are delicious, easy to consume, and it’s not difficult to make a shake that’s packed with over 1000 calories.

I currently use the MyProtein Impact Whey (you can find the cheapest price here). Each scoop packs 21g of protein and 100 calories.

Lean powders like this are a perfect supplement for those who are already able to get most of their protein and calories from whole foods. They also work great in a smoothie.

If you’re new to bulking though, a weight gainer like this Optimum Nutrition Serious Mass (you can find the cheapest price here) may be more suitable. Each serving contains a whopping 50g of protein and 1250 calories.

Weight gainer powders aren’t great for smoothies because they already have a thick consistency. They should just be consumed as they are.

But just make sure you use it as a “supplement” as it is intended and not as an outright meal replacement.

How To Work Out To Gain 10lbs Of Muscle With A Fast Metabolism

Heavy weight training with progressive overload is the best way to gain 10lbs (5kg) of muscle on fast metabolism. An individual should use a weight that challenges them for 8 to 12 reps, and increase weight by 5 to 20% whenever the current weight load becomes easy to perform.


Gaining 10lbs of total body weight is not that hard.

But gaining 10lbs of muscle weight is much harder.

Performing regular resistance training can help you gain 10lbs of muscle rather than 10lbs of excess belly fat.

This is highly recommended and what most people are hoping to achieve anyway when they say they want to gain weight.

A full-body training split is the most beginner-friendly way to build 10lbs of muscle with a fast metabolism.

Aim to complete 3 workouts per week.

Each workout should be separated with at least 24 hours of rest.

Additionally, each workout should comprise other following compound exercises:

ExercisesSetsRepetitionsRest Between Sets
Bench press48-122-3 minutes
Shoulder press48-122-3 minutes
Bent-over row48-122-3 minutes
Goblet squat48-122-3 minutes
Deadlift48-122-3 minutes

Together, these 5 exercises will train your whole body.

Use a heavy weight that challenges and fatigues your muscles with 8-12 reps and keep adding weight whenever the exercise becomes easy.

This is called progressive overload and doing this regularly will keep your muscles growing.

Just make sure the weight isn’t so heavy that your form breaks down.

It’s always better to reduce weight to maintain your form.

You can also include light cardio on your rest days.

This is good for general and cardiovascular health.

But I’d highly recommend limiting cardio workouts to short and intense 15-30 minute sessions. Any longer risks affecting your muscle gains.

If you’re interested, you can also check out my essential tips to gaining your first 10lbs of muscle here.

Choosing The Right Equipment To Gain 10lbs Of Muscle

Resistance training can be performed at the gym where you have ready access to all types of free weights such as barbells, dumbbells, and kettlebells.

Or you can buy your own equipment from Amazon (home workouts are much cheaper in the long run and can save you a lot of time).

If you choose to go down this route, I prefer dumbbells for their versatility, space-saving, and affordability.

I use the Powerblock Elite adjustable dumbbells (you can find the cheapest price here).

Each dumbbell replaces 16 pairs of dumbbell weights. These increments are packed into one neat unit that can be quickly adjusted with a click of a pin.

If you’re looking for a budget alternative, then the Yes4All spinlock dumbbells (you can find the cheapest price here).

Both dumbbells are heavy enough for the average beginner to gain 10lbs of muscle at home.

But the Powerblocks have smaller and more numerous weight increments (great for targeting both small and large muscle groups).

They can also be upgraded to heavier poundages with separate addon kits. This is something the Yes4Alls can’t do (you’re essentially stuck with that weight unless you buy another dumbbell).

How To Keep Track Of Your Weight Gain Journey

Taking a weekly body weight average using digital scales is the best way to monitor the results of a weight gain program. Daily measurements should be taken every morning before going to the toilet. Taking a 7-day average reduces the impact of natural body weight fluctuations on recordings.

Aim to increase body weight by 2 to 4  pounds per month for a healthy rate of weight gain.

I use the Fit Index scale (you can find the customer reviews here).

But any digital bodyweight scale will do the job if it measures in pounds to at least 1 decimal place.

It will take approximately 3-5 months to gain 10lbs (5kg) of total body weight and around 12 months to gain 10lbs of pure lean muscle mass.

You should aim to increase your weight by 0.5 to 1lb per week (or 2 to 4 lbs per month).

You can also aim for a higher rate of weight gain, but you risk putting on more fat.

That’s there’s only so much muscle you can gain in a set period of time (around 2lbs per month as a beginner).

Other things to track include:

  • Calorie intake. Record how many calories you are eating per meal.
  • Protein intake. Record how many grams of protein you ‘re eating per meal.
  • Weight training progress. Keep track of the weight you are lifting on each exercise.

Logging your progress in this manner allows you to identify and troubleshoot issues with slow rates of weight gain.

For a realistic timeframe for transforming a skinny frame into a muscular physique, you can go to my other post which details how long it takes to build big muscle.

Why Do Skinny People Have A High Metabolism?

Skinny people can have a high metabolism due to genetic and external factors. A high basal metabolic rate leads to a fast metabolism, and basal metabolic rate is in turn influenced by genes, exercise level, and daily activities. But this applies to all people, not just skinny people in particular.

Your final metabolism is influenced by 3 main factors:

  • Basal metabolic rate (BMR). This is the energy required to keep your body alive and moving. BMR varies naturally between individuals.
  • Exercise level. Increasing your physical activity levels will also increase the amount of daily calories you expend.
  • Daily activities. Physically strenous lifestyles and jobs will also increase the amount of daily energy you burn.

Your BMR is partly genetic. But it’s also affected by your exercise level and daily activities.

If you’re performing intense weight training or work a strenuous physical job, then your BMR will be higher than if you lived a sedentary lifestyle.

But this applies to everyone and not just skinny people.

From personal experience and research, skinny people don’t just struggle with a fast metabolism.

They also struggle with eating enough food to meet the demands of their metabolism and more (to put on weight).

For example: it’s not uncommon for a skinny person to find out just how little calories they are consuming when they actually start counting their calories.

My best advice is to establish your maintenance calories as accurately as possible, then establish your surplus calories, and slowly increase your calorie intake to reach your target surplus.

All the while you should be calorie counting for at least the first 3-6 months of a bulk.

This will give you a quantitative measure for how many calories are in a typical meal, rather than basing your numbers on guesswork.

If you’re looking to gain weight ASAP (regardless of whether it’s muscle or fat), you may be interested in my other post to find out how to gain 10lbs of body weight in a week.

Recommended Products Recap To Put On 10lbs Of Lean Mass At Home


I’ve explained how to gain 10lbs (5kg) as a skinny male/female with a fast metabolism.

Whilst a sky-high metabolism may be a contributing factor as to why you struggle to gain weight, more often than not, it’s not the only factor.

For most skinny guys and girls, the issue lies with not eating enough nutrients.

The solution is to quantify how many calories and protein you actually need on a daily basis.

This can be done by following the simple processes detailed in the post.

Then you can start working on slowly increasing your meal consumption to reach your nutrition targets.

Oh and don’t forget- a good resistance training program will help ensure that weight is being gained from muscle and not body fat!

You might also be interested in my 11 tips for building muscle as a skinny person!

How will YOU be hitting your nutrient targets to gain 10lbs?

Let me know in the comments!

You may also be interested in the downloadable Kalibre Blueprint PDF which details exactly how I gained 40lbs of lean muscle (it’s 100% free!). It details the exact exercises and nutrition I used to go from skinny to ripped!

Thanks for reading guys!

Peace Out,


(Biochemistry BSc, Biomedical Sciences MSc, Ex-Skinny Guy)

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