Gain 10 Pounds In 2 Weeks: Why And How It’s Possible For Skinny Guys To Put On 5kg In 14 Days

Gain 10 pounds in 2 weeks

Skinny people who have been chronically underweight often want an immediate plan to gain weight fast. This post explains why and how a skinny person can gain 10 pounds (5kg) of body weight in 2 weeks.

A skinny person can gain 10 pounds in 2 weeks by consuming 25,000 to 35,000 surplus calories in 14 days. The total amount of calories required will depend on the individual’s maintenance calories. Furthermore, eating calorie-dense foods is highly recommended for fast weight gain.

Having been an ex-skinny guy in the past, I know your pain.

So I wanted to share my research and experience on how to pack on mass quickly.

Let’s go!

How I would gain 10 pounds (5kg) in 2 weeks based on my 5 year bulking experience as an ex-skinny guy.


I have a B.S/M.S. in biomedical sciences, used to be a skinny person myselfand have 5 years of experience in different bulking methods. But I have not personally tried the exact practices detailed in this content. This content is purely theoretical and based on what I know from scientific research and personal experience. Whilst the concepts would work, they would also be undoubtedly extremely unhealthy.
Please consult a doctor/physician before taking on any extreme weight gain venture.

Can You Gain 10 Pounds In 2 Weeks?

It is possible to gain 10 pounds (5kg) in 2 weeks by consuming an extreme calorie surplus. The average skinny person will need to eat more than double their daily recommended calories. It should also be noted that this added weight will mostly be from fat and not lean muscle.

Why Do We Gain Weight?

You may also find WebMD’s explanation of weight gain useful!


Weight gain is a simple process when you strip it down to its fundamentals.

If you eat more calories than your body burns, then these excess calories (aka surplus calories) will be used to put on weight.

This added weight can either be as body fat or lean muscle tissue.

Now the question is HOW much weight can you gain in 2 weeks”.

Generally speaking, a skinny man or woman can gain up to 10lbs, and more, in 2 weeks. The exact amount of weight gained will be determined by how many surplus calories they can consume in 14 days. The more calories consumed, the more weight can be put on.

You would need to eat approximately 2500 calories MORE than your recommended daily intake (which is 2500 for the average man or 2000 for the average woman) to gain 10 pounds in 2 weeks

This represents a calorie surplus of 100 to 150%, respectively.

Now, this is considered to be a fast rate of weight gain.

And when you put on weight so quickly, most of it will come in the form of fat rather than lean mass.

So whilst, it’s possible to put on 10lbs in 14 days, it’s by no means healthy.

How Does A Skinny Person Gain 10 Pounds In 2 Weeks?

The best way to gain 10 pounds (5kg) in 2 weeks is to increase meal frequency and eat more nutrient-dense ingredients. This increases the likelihood of entering an extreme calorie surplus. Weight training can also be done to put on muscle mass, but extra calories should be consumed accordingly.

In support of this, I tracked down a Quora thread which asked coaches, trainers, and ex-skinny people:

How to gain 10lbs in 2 weeks?

How Quora users would gain 10lbs (5kg) in 2 weeks.

77% agreed the best way to gain 10 pounds in 2 weeks is to eat more food to put yourself in a calorie surplus.

Of those who said you should eat more food, a further 41% agreed that calorie-dense ingredients are the ideal foods to eat.

I share my favorite calorie-dense foods later in this post.

But now you may be wondering:

Exactly how many daily surplus calories do I need to eat to gain 10 pounds in 2 weeks?

As mentioned previously, the short answer is around 2500 calories per day.

And here’s why:

  • It takes 2500-3500 surplus calories to gain 1lb of body weight.
  • Therefore you would need 25,000 to 35,000 total surplus calories to gain 10lbs.
  • This equates to 1800 to 2500 surplus calories per day to gain 10lbs in 2 weeks.

These are surplus calories by the way.

This means they should be consumed on top of your current maintenance calories.

Maintenance calories are burned by your body to maintain your current weight.

Everyone burns a different amount of maintenance calories.

How to determine your maintenance calories:

The easiest way to determine yours is to use the TDEE calculator here.

For example- a sedentary 25-years-old 120lb male requires 1800 maintenance calories per day to sustain their body weight. Adding 1800-2500 surplus calories would mean he would need to consume 3600-4300 total calories per day to gain 10lbs in 2 weeks.

And if you’re lifting weights (intending to build muscle weight), then you should add an extra 300-500 calories to your training days.

The same calculations can be applied to men and women of different body weights. The only variable here is your maintenance calories (which can be determined as per the above instructions).

Is It Healthy To Gain 10 Pounds In 2 Weeks?

Generally speaking, it is not healthy to gain 10 pounds (5kg) of body weight in 2 weeks. This is considered to be a relatively fast rate of weight gain. As a result, most of the weight gained will be from excess body fat rather than lean muscle tissue.

Sanford Health recommends a healthy weight gain rate of 1 to 2 pounds (0.5 to 1kg) per week.

This increases the likelihood you will gain healthy weight (i.e. muscle) rather than unhealthy weight (i.e. body fat)

You should also note that muscle tissue can only be put on through regular resistance training (see the end of the post).

“As you put on weight, the goal should be to increase an appropriate amount of lean muscle, not simply body fat.”

Sandford Health

But you can’t expect to lift weights 24/7 and expect fat gains to magically turn into muscle gains.

It doesn’t work like that.

The issue is that we all have an upper limit to how much muscle mass we can put on in a certain period.

A male beginner can typically only gain a maximum of 1-2lbs muscle per month (or 0.25-0.50lbs muscle per week).

And that’s by following an optimized workout and nutrition plan.

Why gaining 10 pounds (5kg) in 2 weeks is unhealthy.

If you do this, you can expect to gain up to 0.5 to 1lb of muscle mass in 2 weeks.

So whilst it’s possible to gain 10 pounds in 2 weeks, around 90% will be from fat and the remaining 10% muscle (no matter how much you train).

And since excess body fat is generally unhealthy, putting on 10 pounds in 2 weeks is by extension also unhealthy.

With that being said, 10lbs of fat may be a welcome change if you’ve been chronically underweight for most of your life!

For a more sensible approach to gaining weight, you might want to check out my 9 ninja tips to pack on 10lbs lean mass in 6 months!

How To Gain The Most Weight In 2 Weeks

The easiest way to gain the most weight in 2 weeks is to establish your calorie surplus target and eat nutrient-dense foods to achieve that target. Nutrient-dense foods are usually high in sugar and fats. They provide a lot of calories in a small volume of food.

If you’ve ever tried to bulk up, you’ll know just how difficult it can be to eat surplus calories.

You’ll constantly feel bloated and have a sickeningly “full” feeling.

So it makes sense to focus your diet on the so-called calorie-dense foods that are rich in fats.

Not only are these foods often highly palatable for most people, but they also give you more bang for your buck in terms of reaching your calorie targets.

Why eating calorie-dense foods that are rich in fats is the best way to gain the most weight.

More specifically, a gram of fat contains 9 calories compared to a gram of carbs/protein which only contains 4 calories.

You should also be aware that it’s much easier to gain fat weight than it is to build muscle weight.

So if your goal is to put on as much weight as fast as possible, then skip the weight training and just binge eat.

But as I already established, rapid fat gain is generally unhealthy.

So you need to consider the tradeoff between healthy but slow vs unhealthy but fast weight gain.

For a more sustainable approach to gaining 10lbs (5kg) of muscle, you can check out my 17-step complete guide here.

Best Foods For Weight Gain

Here are some of the best calorie-dense foods you can eat to gain weight fast:

Recommended Foods To Gain WeightTypical Calories Per 100gHealthy Or Unhealthy?
Fatty red meats300 calUnhealthy
Oily fish200 calHealthy
Chicken thigh180 calUnhealthy
Nuts and seeds500-600 calHealthy
Nut butter580 calHealthy
Honey310 calHealthy in moderation
Beans330 calHealthy
Vegetable oils900 calHealthy
Butter700 calUnhealthy
Cheeses400 calUnhealthy
Whole grains (uncooked)320 calHealthy
Weight gainer shakes (per serving)1000 calHealthy in moderation

All these foods are rich in nutrients and energy.

But some are healthier than others.

Healthy calorie-dense foods include complex carbohydrates like whole-wheat pasta, brown bread, brown rice, and oats.

Mono-/poly-unsaturated fats such as those found in nuts, olive oil, and omega-3 oily fish like salmon and tuna are also generally healthy.

Unhealthy calorie-dense foods include refined carbs, sugar, confectionery, and the saturated fats you find in fatty meat, butter, and junk foods.

Both can help you gain 10lbs in 2 weeks.

But try to prioritize healthy ingredients over unhealthy ones.

Make a healthy homemade weight gainer shake by blending protein powder with fruits, olive oil, peanut butter, oats, milk, and honey.

You can also blend protein powders with fruits, olive oil, oats, ice cream, beans, milk, honey, and peanut butter to make a healthy homemade weight gainer smoothie.

Smoothies are great because liquid calories are much easier to consume and don’t leave you feeling full for so long.

I use the MyProtein impact whey.

Each scoop contains 21g of protein with 100 calories.

The shake has a thin consistency which makes it perfect for blending with the above-said ingredients.

A 5.5lb bag will last you around 2 months (depending on how many scoops you have a day).

You may also be interested in my other post to find out how to gain 10 pounds with a fast metabolism.

Best Exercises For Weight Gain

Disclaimer: it’s impossible to gain 10lbs of muscle weight in 2 weeks. The following recommendations are more tips for long-term weight gain.

Compound movements such as the bench press, shoulder press, row, squat, and deadlift are the best exercises to gain weight. These work multiple muscle groups in a single movement. They can be performed with bodyweight training as well as free weights such as barbells, dumbbells, and kettlebells.

I prefer to use dumbbells.

In my opinion, they offer the best balance between affordability, effectiveness, and space-saving.

I use and recommend the Powerblock Elites.

They pack 16 different weight settings into one neat unit, and this is more than enough for a beginner to gain 10lbs of muscle at home.

If you want the cheapest way to do resistance training at home, then bands are also great.

Resistance bands are the cheapest and most convenient way to gain 10lbs of muscle at home.

The Undersun bands are cheap and very convenient to use.

They’re a bit more expensive than the budget Amazon-branded bands, but they come with a lifetime warranty which the others don’t (and I’ve had 2 sets of cheap bands snap on me in the past).

You’ll also want a cheap pair of gloves like the Ihuans to protect your hands from friction burn.

You might also be interested in my other post to find out just how hard it is to gain 10lbs/5kg of muscle.


I’ve explained why and how it’s possible to gain 10 pounds (5kg) in 2 weeks.

You’ll need to consume a total of 25,000-35,000 surplus calories in the space of 14 days.

This equates to around 4000 total calories per day (depending on your maintenance calories).

Just be aware that most (if not all) of the weight gained will be from fat rather than muscle.

As such, it’s not healthy and you should ideally take on a more sustainable training and nutrition program to gain 10lbs of muscle over a longer period instead.

Will you be trying to gain 10lbs in 14 days?

Feel free to send me a message if you have any questions! You can find my details on the “contact us” page.

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 (with printable worksheets) I used to go from skinny to ripped!

Thanks for reading guys!

Peace Out,


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


I'm Kal (B.S, M.S)- a health & fitness writer and owner of Kalibre Fitness. I love to nerd out on weight training and nutrition. My primary interests are in muscle hypertrophy mechanisms and strength development. You can connect with me in the "Contact Us" section below!

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