Is It Possible To Put On 10lbs In A Week? (as a skinny guy)

Is it possible to put on 10lbs in a week.

If you’ve been cursed with the skinny gene like I was, then chances are you’ve thought about gaining some weight…fast. This post explains if it is possible to put on 10lbs (5kg) in a week.

Putting on 10 pounds in a week is theoretically possible. However, the average person would need to consume around 7,000 total calories per day to do so. Not only is this extremely difficult to achieve but also very unhealthy.

I have not personally tried to gain 10lbs in as little as 7-10 days. But I do have extensive bulking experience as an ex-skinny guy.

Keep reading to find out why I would not recommend gaining so much weight so fast.

It took me longer than a week to gain 10lbs.
Information is based on scientific research and my own bulking journey.

Key Takeaways

  • Whilst theoretically possible, most people cannot realistically consume the ~7000 total calories per required to put on 10lbs in 7-10 days.
  • 10lbs can still be gained as fast as possible by going on a bulk and eating calorie-dense foods.
  • It is impossible to gain 10lbs of pure muscle weight in just a week.

How Do You Put On Weight?

Weight gain occurs when more calories are consumed than expended. The excess energy is stored by the body as fat or, if resistance training, used to build muscle. Therefore eating in a caloric surplus is essential for gaining weight.

Why Do We Gain Weight?

To put it simply- overeating is the aim of the game when it comes to gaining weight. This is called putting yourself in a caloric surplus, or “bulking”.

If you enter a calorie surplus without working out (i.e. leading a sedentary lifestyle), then most of the extra calories will be stored as body fat.

But if you follow an effective resistance training program (i.e. lifting weights) whilst in a calorie surplus, then a lot of the extra energy can also be used to build muscle.

Either way, you end up gaining weight.

Why It’s Not Realistically Possible To Put On 10lbs In A Week

Calculation to show why it is very difficult to gain 10lbs in 7-10 days.

It’s not uncommon for underweight people to want to gain weight fast, say put on 10lbs in; 10 days, 7 days, or even a weekend.

Here’s why this is generally considered to be an unrealistic goal that’s not recommended:

Whilst gaining 10lbs of body weight in a week is theoretically possible, the likelihood that a beginner will successfully achieve this goal is pretty low.

You need to eat around 3500 surplus calories for every pound of body weight you want to gain. That’s 35,000 surplus calories to gain 10 pounds.

Furthermore, 35,000 surplus calories over 7 days equate to 5000 surplus calories every day.

And that’s on top of your current maintenance calories (which you already consume on a daily basis to maintain your current weight).

Most people burn around 2000 maintenance calories every day.

Combining your surplus and maintenance calories means you would need to eat around 7000 total calories every day to put on 10lbs in a week.

This is not only extremely challenging (even when you’re purposefully bulking) for most people, but also very unhealthy.

Why It Is Not Healthy To Put On 10lbs In A Week

It usually takes most people around 1 to 2 months of planned bulking to put on 10lbs.

That’s around 1-2lbs per week which is considered to be near the upper threshold for a healthy rate of weight gain. Doing this would require you to eat around 500-1000 surplus calories per day.

Therefore gaining 10lbs in a short period of time- say 7 to 10 days- is considered to be an extremely fast rate. It requires you to eat around 5000 surplus calories per day.

As a result, you would put on a lot of excess body fat very quickly.

And this is generally not recommended.

How Many Pounds Is It Possible To Put On In A Week?

Most people can realistically put on a maximum of 5lbs per week. Whilst there is no theoretical limit as to how much weight gain is possible per period of time, a typical person will find it difficult to consume the extreme numbers of calories required to gain more than 5lbs in a week.

Bulking is not easy for a beginner.
Bulking can be difficult especially for skinny people with a naturally low appetite.

Remember- weight gain simply requires you to overconsume calories. The more you overeat the more weight you gain.

The issue?

There’s a limit to how much food you can comfortably eat in a day.

Speaking from personal experience and researching other skinny people’s journeys, it’s difficult for a beginner to be able to eat much more than 1000 surplus calories per day (it leads to an uncomfortable bloated feeling).

1000 surplus calories per day for 7 days leads to around 2lbs weight gain. You could also try eating more than this to put on more weight.

Is It Possible To Gain 10lbs Of Muscle In A Week?

It is impossible to gain 10lbs of lean muscle mass in a week. Building muscle is a slow process and the rate of growth is limited to around 0.5lbs of muscle per week (max) for the average person.

Putting on overall body weight (including fat) and gaining muscle weight are two very different goals.

Unlike gaining fat, building muscle has a limited rate no matter how hard you train or how much you eat.

With that being said, you could combine your calorie surplus with full-body heavy resistance training to create more favorable conditions for muscle growth.

But don’t expect to put on much more than 0.5lb of muscle weight in 7-10 days.

Realistically speaking, it takes around 1-3 months minimum to gain 10lbs of muscle. And that’s only if you’re following effective muscle-building practices.

5 Tips To Put On 10lbs As Fast As Possible

Whilst it may not be possible to put on 10lbs in a week, you can follow the below bulking tips to do it as fast as possible:

1) Accept That Gaining 10lbs In A Short Timeframe Will Mostly Be Body Fat

It’s important to have realistic expectations for what you can achieve.

Even if you’re following a good resistance training program, gaining 10lbs in such a short timeframe means most of the weight gained will be from body fat.

If this is something you do not want, then it’s worth considering going on a slightly longer bulking program that allows you to maximize muscle gains and minimize fat gain.

2) Aim To Consume 35,000 Surplus Calories

As you know, 35,000 surplus calories are required to put on 10lbs.

Even if you’ve now decided that it’s unrealsitic to put gain 10lbs in 7-10 days (after reading this post), it’s still important to track your calorie intake, regardless of the timeframe which you plan to gain that weight in.

Plan each meal in advanced. Log the exact number of calories in each meal.

This gives you the best chance of successfully gaining 10lbs as fast as possible.

3) Utilize Calorie Dense Foods

These are foods that have a lot of calories despite a relatively low volume:

Calore-Dense FoodCalories Per 100g
Fatty meat like pork belly520
Ribeye Steaks400
Oily fish like salmon and mackerel210
Whole grains like oats and wheat320
High-fat cheeses400
Heavy cream and coconut milk340
Nuts and seeds580
Vegetable oils like olive oil (per 100ml)900
Weight gainer protein shakes (per serving)500-1000

Calorie-dense foods are an easy way to consume a lot of calories with minimal bloating.

4) Find Delicious Ways To Consume Liquid Calories

Liquid calories are one of the best ways to gain weight fast. These types of meals are easy to consume and fast-digesting.

This allows the you to ingest a high amount of calories without a prolonged satiation (that “full-feeling” after a heavy meal) that can last for hours after a large conventional meal.

Trust me.

Drinking a 1000 calorie shake is much easier than eating a 1000 calorie meal!

5) Plan A Pre-Bed Meal Every Night

A pre-bed meal that is high in calories and protein can help a person gain 10lbs asap.

Pre-bed nutrients will keep the body supplied with a source of energy during what would otherwise be a fasted state. This can help you to gain weight faster.


It is theoretically possible to put on 10lbs in a week. But practically speaking, most people will not be able to succeed.

It requires you to eat 35,000 surplus calories in 7 days which most people cannot do.

However, you can still try to gain 10lbs as fast as possible by going on a bulk and consuming high-calorie meals multiple times per day.

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 printables) I used to go from skinny to ripped!


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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