How To Gain Weight?

Written by Andrew Brewer. ⚕️Reviewed and fact checked by Dr. Harshi Dhingra.


For many of us gaining weight is as easy as eating a couple of donuts. For others however, gaining weight can prove to be quite difficult. While most people wouldn’t look at being underweight as anything to be concerned about, the truth is being underweight can be just as dangerous as being overweight.

If you are clinically underweight, or you are just having a hard time putting on some muscle weight, this article is for you.

Below we will discuss what it really means to be underweight, some of the common causes of being underweight, health risks associated with being underweight and what you can do to put on weight in a healthy, quick, and easy manner. In other words, you will learn how to gain weight, just keep on reading.

Key Takeaways

  • Being underweight can be just as dangerous as being overweight, and it is important to address this issue if you are clinically underweight or having a hard time putting on muscle weight.
  • There are a variety of reasons someone can become underweight, including genetics, metabolism, and living situations. Some of the most common causes include a lack of appetite, thyroid problems, digestive problems, depression, and eating disorders.
  • If you want to gain weight in a healthy, quick, and easy manner, it is important to focus on increasing your calorie intake, building muscle through exercise, and eating a balanced diet that includes protein, healthy fats, and complex carbohydrates.
  • Women and young girls are more likely to be underweight than men, and it is important to seek professional care if you are struggling with depression, eating disorders, or other health issues that may be contributing to your weight loss.
  • While BMI calculators can be a helpful tool for determining if you are underweight, it is important to keep in mind that they may not be entirely accurate and that other factors, such as muscle mass, can affect your weight and overall health.

What Does It Mean To Be Underweight?

If you have a BMI, or body mass index, of 18.5 or lower, you are considered underweight. You are also considered underweight if your weight is 15% to 20% below what is normal for your height and age. On the other end of the spectrum is being overweight or obese. If your body mass index is over 25, you are considered overweight. If it’s over 30, you are considered obese.

To find out if you are underweight based on your height, use this free calculator provided by the National Heart, Lung, and Blood Institute.

The Calculator

Though using calculator is a good guide, it is not the end all be all. Most of these calculators only look at your height and weight when determining your BMI. They completely overlook the amount of muscle you have on your frame.

Because of this these numbers can be somewhat off. Some people are solid muscle and are therefore outside of what is considered a “normal” weight. However, that doesn’t mean they are unhealthy.

On the other hand, just because someone is skinny doesn’t mean they are healthy or do not have a health problem.

Interesting Facts You Should Know

Women and young girls are as much as 3 times more likely to be underweight than their male counterparts. For instance, in the United States 2.4% of women over the age of 20 are underweight while just 1% of men of that same age are underweight.


What Can Cause Someone To Become Underweight?

There are a variety of different reasons someone can become underweight. It can be due to genetics, metabolism or living situations. In some cases, extreme poverty is the root cause of someone losing a lot of weight in a short period of time.Here are 10 of the most common reasons someone would become overweight:

Lack of Appetite

There are many different factors and conditions that can lead to a lack of, or complete loss of, appetite. Some of these conditions are only temporary and your appetite will return once they subside.Here are a few conditions that can lead to a lack of appetite:

  • Dementia
  • Crohn’s disease
  • Liver disease
  • Mumps
  • Kidney failure
  • Stress
  • Pancreatitis
  • Rheumatoid arthritis

Thyroid Problems

If you have an overactive thyroid it may be causing you to lose weight at a rapid pace. When you have an overactive thyroid, which is medically known as hyperthyroidism, it means your thyroid gland is making and releasing the thyroid hormone in excess. Usually it is making more than your body needs.

Everything from your brain, to the muscles that make up your body are affected by the hormones released by the thyroid gland.

These hormones play a crucial role in how your metabolism operates.

Some things that can lead to an overactive thyroid include Graves’ disease, excess iodine, thyroid nodule and thyroid medications.

Digestive Problems

Digestive issues such as irritable bowel syndrome and Crohn’s disease can lead to unintentional weight loss. According to John Hopkins Medicine, close to 100 million Americans are dealing with some sort of digestive problem.When you are dealing with a digestive problem, the nutrients you consume don’t get properly absorbed. When this happens your body is unable to metabolize the nutrients from the food. As a result you lose weight, irrespective of how much food you eat. General symptoms of digestive problems include bloating, diarrhea, constipation and nausea.


Million of people all over the world are dealing with depression on a daily basis. When you are depressed, your appetite goes away.

You simply don’t want to eat. And as you very well know, if you don’t eat, you will lose weight. If you are suffering from depression please seek out professional care immediately.

Eating Disorders

Anorexia and bulimia are two very serious eating disorders that can lead to extreme weight loss. Most people who suffer from these eating disorders have a body weight that is dangerously low. According to the American Psychological Association, people who suffer from anorexia tend to have body image issues. People who have bulimia are often times found to have a normal weight. However, it’s the constant purging that leads to them losing too much weight in a short period of time.

Either way, when people suffer from either of these eating disorders, they are usually overly obsessed with dieting and losing weight. Both are very serious conditions and should be dealt with immediately.

Celiac Disease

Most people who have Celiac disease have no idea they have it. When you have Celiac disease it means you have an intolerance for gluten. If you eat a food that contains gluten, it can lead to you getting sick.

When you’re sick you don’t want to eat which means you end up losing weight.

Uncontrolled Diabetes

If you have diabetes please take a good care of yourself. Eat healthy and get plenty of exercise. Otherwise you may end up losing a ton of weight, or even worse, end up losing a limb.


Some forms of cancer can cause you to burn unbelievable large amounts of calories. As a result you will lose a lot of weight. The treatment of cancer can also lead to weight loss. Things such as radiation often lead to a loss of appetite.

A Fast Metabolism

When you have a fast metabolism, gaining weight is by far one of the most difficult things to do.

Usually it’s your genetics and body type that lead to a fast metabolism. The best way to combat this situation involves eating foods that metabolize slowly.

You Aren’t Eating Enough

In some cases, you simply are consuming enough food. Your body uses up so many calories for energy every single day. If you aren’t consuming more calories than your body burns, you are going to lose weight. The key is to start eating more of the right foods which we will discuss later.

The Dangers of Being Underweight

As previously stated, being underweight is just as dangerous as being overweight. Both conditions can lead to a variety of different illnesses and in some cases, even death.

The National Center for Biotechnology Information has done several studies on the link between being underweight and dying prematurely. One study showed that men who were underweight had a 140% greater risk of dying early than those who were of a normal weight. In women the risk was 100%.


Besides the risk of early death, malnutrition is also a serious problem that can result from being underweight. By definition, malnutrition is when you fail to consume an adequate amount of nutrients.

There are a lot of different things that can happen when your body isn’t getting the nutrients it needs to function. For example, if you aren’t getting enough vitamin C, you are more susceptible to getting scurvy. If you don’t get enough iron, you may become anemic.

On top of that, when you aren’t getting the right nutrients, your immune system takes a serious hit. In such situations you will find yourself catching a common cold and having a difficult time recovering from it.

You will also find that wounds take longer to heal.


In 2010 the Baltic Journal of Health and Physical Activity published a study that showed individuals who were underweight had a lower bone mass density than those who were not.

Nasim Habibzadeh, who was the author of the study, also pointed out that low bone mass density can ultimately lead to osteoporosis. When you have osteoporosis it means your bones will be fragile and brittle. Those who have osteoporosis often suffer from broken or fractured bones for no apparent reason. While osteoporosis is usually most common in women who are post menopausal, its is not uncommon to develop it at a young age when you are underweight.

Here’s the bottom line, being underweight is nothing to play with. If you think you are underweight, educate yourself on ways you can prevent it.

If you think its due to a medical reason, seek professional help as soon as possible.

5 Steps To Gain Weight Naturally


Now that we know how people become underweight and what it can do to their health, let’s talk about what you can do about it.

Most people would look at gaining weight as a license to eat whatever they want. And yes, technically speaking you can eat a ton of junk and gain weight. However, it’s not the best way to go about it.

Especially if your goal is to not only gain weight, but to be healthy in the process.

Keep in mind when you are underweight, chances are you have a few nutritional deficiencies that need to be addressed.

So just like you would take a balanced approach to losing weight, you should also take a balanced approach to gaining weight. The idea is to gain muscle mass and not a ton of excess fat.

To maximize your healthy gains, try these healthy and effective weight gaining tips:

Step 1: Consume More Food

How-to-Start-Working-OutIf you want to gain weight you have to create what is known as a caloric surplus. In other words, you need to consume more food than your body needs on a daily basis. To determine your total daily energy expenditure you will need to use a calorie calculator.

There are several free ones online. Personally, I love this one.

Use calculator to determine how many calories you need to eat to maintain your current weight. If you are looking to gain weight fast, consume an additional 750 calories every day.

While tracking calories is not a necessity, it is recommended. This way you know you are creating the needed caloric surplus to gain weight each week.

Step 2: Be Smart About The Calories You Consume

food-high-in-proteinJust because you need to eat more doesn’t mean you should eat anything and everything. For best results, you need to be smart about the calories you consume. For instance, focus on foods that are calorie rich and nutrient dense.

Whether you are trying to lose weight or gain weight, protein should always be a staple in your diet. You want muscle? You need protein. Otherwise, any gains you make will turn into ugly body fat.

Studies have shown when you are in a caloric surplus, consuming a high protein diet will help all the extra calories turn into muscle.

Be Careful About Too Much Protein

However, be very careful with the amount of protein you consume. Protein will fill you up which can often times lead to a reduction in appetite. As a result, you may find it even more difficult to gain weight. Ideally, you should stick with anywhere between 0.7 to 1 grams of protein per pound of body weight, (more about protein intake). If you have a very high calorie intake, it’s okay to consume even more protein.

Some of the best sources of protein include lean meats such as chicken and fish, nuts, a variety of different dairy products and eggs. Protein supplements are also a great source of protein. We will discuss which protein supplements you should consider taking in further detail below.

Fat is another important food source for those trying to gain weight. Fat has 9 calories per gram. That’s nearly twice as many calories as protein and carbs. Your body also burns fewer calories when digesting fats.

The great thing about fat is that it can easily be added into your diet. For instance, Olive oil is not only calorie rich, but it’s a great source of healthy fats. Don’t worry about consuming too much fat. According to research, there is very little evidence linking cardiovascular disease with the amount of fat you consume.

Step 3: Lift Heavy Weights

You want to get big, you have to lift big. Once you have your nutrition in line, its time to hit the weights. As long as you are applying some form of resistance to your body, you will build muscle and put on weight.

According to, if you want to put on some serious mass, your exercise regimen  should include strength and hypertrophy protocols. This basically means you should perform 3-4 sets using a weight that’s around 80 percent of your one rep max. When you train this way, rest time is extremely important. You want to give yourself enough time for your muscles to recover and get ready for the next set. You should rest between 1 and two minutes.

What Exercises Should You Do?

The exercises you do are just as important as the type of protocol you use. The best exercises for packing on the muscle are squats, rows, the shoulder press, deadlifts and the bench press.

Leg curls and leg extensions are also great exercises for putting on size.

Step 4: Take Supplements


Supplements were created to help you reach your goals. If you have ever tried to put on weight or muscle, you know it can be extremely difficult. And that’s where supplementation comes into play.

There are four main types of supplements you can take to gain weight. A weight gainer, dextrose, ZMA and creatine,. Let’s briefly discuss each one.

Weight Gainers

Weight gainer supplements are always a good investment for those looking to gain weight. Most weight gainers come loaded with fat, carbs and protein. That means one weight gainer shake could easily consist of 500 to 1000 calories per serving.


Dextrose is a carb source you can easily add to your diet. You can add it to your pre, post and during workout shakes. Compared to other weight gainers, dextrose is very cheap. You can buy it in bulk without breaking the bank.


One of the most important aspects of muscle growth is recovery time. To speed up recovery consider taking BCAA. When it comes to muscle recovery and repair, BCAA is a leading supplement. For best results, take this supplement right before you lay down for the night.

Not only can BCAA help with muscle recovery, but it can also help with muscle strength and size.


Creatine is probably one of the most popular weight gaining supplements on the market. Supplementation with creatine increases strength and improves physical recovery. Creatine absorption in the body gets improved if taken with carbohydrates, so it is taken with a small amount of food to maximize its effects.

Creatine has been around for a very long time and is one of the most studied supplements available. And based on the evidence, it works. It is recommended you take as much as 3-5 grams per day.

Step 5: Get Plenty of Sleep

sleep-for-weight-lossAlways remember supplements are just supplements. They supplement what you are already doing. If your diet and exercise regiment aren’t where they should be, no supplement in the world will help you.

There is a reason why we were taught to get at least 8 hours of sleep every night. Not only does sleep help your body heal itself, it also helps your muscles recover. Patience and Consistency The Keys To Long Term Success. Keep in mind your muscles don’t grow while you are working out, they grow while you are asleep. So don’t short change yourself when it comes to sleep. Doing so could have a negative impact on your gains.

Putting On Weight Is Not Easy

It can take some people several months to put on just a few pounds. This is because your body has a specific weight where it feels most comfortable. Once it gets to that weight, it will do everything it can to make sure it remains there.

When you start consuming more calories, your body will try and combat that by boosting your metabolism and suppressing your appetite. It’s really awesome when you think about it. The body is truly an amazing instrument.

And because your body responds this way to the increase in calories, you can expect to run into a few road blocks while you are trying to gain weight. In some cases you may have to continue eating even though you are already stuffed. That’s why it is so important you are both patient and consistent. You have to be in this for the long haul. If you are expecting to put on 30 pounds of muscle in the next 3 months you have another thing coming. That’s just the nature of the beast. And if you are serious about gaining weight, you will have to do what needs to be done.

It may sound cliché, but look at gaining weight as a marathon and not a sprint. In other words, you need to be able to go the distance. For best results you need to give yourself at minimum 6 months to see any noticeable results.

That’s also why it is so important you track everything. Measure yourself once a week. If the scale isn’t moving in the right direction, make a few tweaks to your diet. Something as simple as consuming an additional 250 calories per day may be all you need to get the scale moving upwards again.


If you focus on eating the right foods and lifting heavy weights, not only will you improve any nutritional deficiencies you may be dealing with, but you will also gain weight and create an amazing body in the process. So just stay motivated, don’t look for any shortcuts, keep working out, keep sleeping and keep eating! There are no best ways how to gain weight, there is only one way, the right way!


  • Why do some people struggle to gain weight?

There can be a variety of reasons why some people struggle to gain weight, including genetics, a fast metabolism, high activity levels, or underlying health conditions.

  • How can I determine my daily calorie needs for weight gain?

You can calculate your daily calorie needs using an online calculator or consulting with a registered dietitian.

  • Is it better to gain weight through diet or exercise?

While exercise is important for overall health and muscle gain, diet is the primary way to gain weight. You need to consume more calories than you burn to gain weight.

  • What are some healthy foods to include in a weight gain diet?

Some healthy foods to include in a weight gain diet include lean proteins, complex carbohydrates, healthy fats, fruits, and vegetables.

  • Should I focus on eating more protein to gain weight?

Protein is important for muscle growth and repair, but it is not the only nutrient necessary for weight gain. Therefore, it’s important to consume a balanced diet that includes carbohydrates and healthy fats as well.

  • How much weight can I realistically expect to gain per week?

The amount of weight you can realistically expect to gain per week depends on several factors, including your starting weight, age, gender, and calorie intake. A safe and healthy rate of weight gain is around 1-2 pounds per week.

  • Is it necessary to take supplements to gain weight?

No, it is not necessary to take supplements to gain weight. Instead, a balanced diet that includes a variety of nutrient-dense foods should provide you with all the necessary vitamins and minerals to support weight gain.

  • Can I gain weight without eating junk food?

Yes, you can gain weight without eating junk food. It’s important to focus on consuming nutrient-dense foods that are high in calories, such as nuts, seeds, avocados, and whole grains.

  • How long does it take to see results from a weight gain diet?

The amount of time it takes to see results from a weight gain diet can vary depending on several factors, including your starting weight, calorie intake, and exercise routine. It’s important to be patient and consistent with your diet and exercise habits to see the best results.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!