How to Gain Weight If I'm Too Thin

Lift weights to help gain weight.
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While there are reams and hours and gigabytes worth of information available to people who are trying to lose their extra pounds, it can be hard to find resources if weight gain is your goal. There are many causes for being underweight, from basic genetics or a sudden growth spurt in an adolescent to illness, treatment of an illness or an eating disorder.


Simply packing on the pounds is a cakewalk if you binge on high-fat, sugar-filled empty calories such as those found in fast food, fried foods, cakes, cookies and chips, washing it all down with gourmet coffee drinks slathered with whipped cream.

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Simple, yes ⁠— but disastrous for your health in the long run. The healthiest and most effective way to gain weight is through a combination of nutritious meal planning, muscle-building workouts and, if necessary, counseling to retrain attitudes about food.


Understand Underweight Dangers

Mothers, aunties and nonnas from time immemorial have urged their loved ones to, "Eat, eat ⁠— you're so skinny!" and it could be that they're onto something. According to the fitness experts at Ohio State University, female runners who are underweight have a higher number of stress fractures than their more robust counterparts. In addition, it took these women longer to heal from an injury when one did occur.


Being at a healthy weight is also important for people who are dealing with health issues such as cancer, advises the Roswell Park Comprehensive Cancer Center. Being overweight can bring a host of health problems, but so can being underweight. Both conditions can have a negative impact on your ability to tolerate treatments such as chemotherapy, radiation and surgery, cautions Roswell Park.

Being underweight can also increase your susceptibility to hepatitis E if you are pregnant, according to Johns Hopkins Bloomberg School of Public Health. So being underweight is a matter of more importance than just not filling out those jeans or stretching that muscle shirt out of shape ⁠— it can have a truly adverse effect on your health.


Assess Your Current Weight

Your first step is to consult a physician or other health professional to make sure that you do, in fact, need to put on some pounds. Snapchat culture and the constant presence of both social media and the images of celebrities facing you at every turn can give you a distorted idea of how your body looks in comparison to those images.

In extreme cases, according to the experts at the University of Rochester Medical Center, a skewed view of your body can develop into body dysmorphic disorder, or BDD, in which you become hyper-focused on perceived flaws to the point that it interferes with your normal functioning. So it is important to make sure you are not already within a healthy weight range before you try to gain more.



One of the ways to assess your weight, says Columbia University's Go Ask Alice! advice site, is to look at your Body Mass Index, or BMI. Measure your height and your weight and compare them to a BMI chart, Alice advises. If your weight is within the normal range for your height, you may want to consult a mental health provider to help you understand why you think you need to gain weight.

Read more: 26 Stars Who've Struggled With Body Confidence


Know the Underlying Causes

Before you can formulate a plan for healthy weight gain, it's a good idea to figure out why you are underweight to begin with. Knowing the cause can help you remedy the issue so that you have an easier time gaining needed weight, and it may give you signs to watch out for so that you do not end up underweight again.

According to Taylor Wolfram, MS, RDN, LDN, at the Academy of Nutrition and Dietetics, there are several possible causes for becoming underweight. They can include but are not limited to:


  • Genetics
  • A sudden growth spurt
  • Illness
  • Reaction to medication or medical treatment
  • Parasites
  • Emotional trauma
  • An eating disorder

Some people are just naturally thin, Wolfram explains. If your family is made up of thin people, you may not have much success at extreme bulking up. Sudden growth can cause adolescents to become underweight, but with proper nutrition, they usually go back to a normal weight. Illnesses like celiac disease can inhibit food absorption, while medications and medical treatments can suppress your appetite as can emotional traumas and eating disorders. Parasites are uncommon, but if you suddenly lose a lot of weight after traveling, see your physician.


Plan a Smart Weight Gain

It is not enough to merely count calories, caution the experts at the University of New Hampshire. They recommend that you pay attention to the quality of those calories as well. Create a plant-based meal plan that includes a wide variety of vegetables, fruits, protein, carbohydrates and healthy fats. Stay away from processed foods and those containing preservatives and artificial colors and flavors. These will certainly pack on the pounds, but they can also take a toll on your health.


Start with at least five servings of fruits and vegetables per day. You should also include starchy carbohydrates such as pasta, bread and rice ⁠— counter to advice for losing weight, which concentrates on complex carbohydrates. Being underweight can cause weakness and fatigue, cautions the University of Rochester Medical Center, and can impair your body's ability to resist infection or recover from illness or wounds.

You need protein to build muscle, so eat plenty of beans, beef, chicken, eggs, fish pork and turkey. Have fatty fish such as salmon and mackerel at least twice every week. Stay away from artificial spreads such as margarine, which contain harmful trans fats, and concentrate on healthy fats such as those found in avocados and olive oil. These are fairly high in calories, but the fat they contain is not harmful and actually helps lower your level of "bad" cholesterol.

Read more: The 4-Week Meal Prep Challenge

Build More Muscle

Having more muscle than fat will not only make you look better, but it is better for your health overall, advise the experts at the International Sports Sciences Association. Building muscle is not complicated, ISSA reassures, but it requires hard work ⁠— in order to build muscles, you first have to work them to the point of fatigue. This means sweating and grunting and being sore the next day. The good news, ISSA reassures, is that this muscle hypertrophy is not necessary to build muscle in beginners.

The other good news, ISSA points out, is that eating plenty of protein and carbohydrates, plus supplementing with leucine, can help you build muscle a little faster. Leucine can be compared to a light switch: It turns on your muscles' ability to synthesize proteins, which they need to do to repair and to build lean muscle mass.

If you do not want to take any supplements, that is also OK. Texas A&M University Health Science Center explains that eating a 40:30:30 diet is an effective and natural way to build muscle. This diet consists of 40 percent protein such as chicken, fish, eggs, beef and pork. Next comes 30 percent carbohydrates. Because you are not trying to lose weight, you can enjoy both simple and complex carbs, as long as you stay away from empty, sugary ones like pastries and chips. The final 30 percent should consist of healthy fats.


Count Your Calories

Smart dieters plan ahead and do their prep work to help ensure they achieve their weight loss goals, and this strategy will also be effective for you as you work to gain weight. And just as people trying to lose weight often underestimate their portion sizes, as described by the experts at Tufts University, it is likely that you may be overestimating yours and not getting the calories you need to put on weight.

If it takes a deficit of 3,500 calories to lose 1 pound of fat then it follows that it takes an extra 3,500 calories to add a pound of fat. The quality of the food you consume is far more important than the quantity if you are aiming for healthy and sustainable weight gain, but counting calories is a good place to start until you become more adept at estimating portion sizes.

Calculating how many calories you need in order to gain weight may involve a bit of trial and error because differences in metabolism, age, gender, health and activity level ensure that no two people's weight gain will be the same. Start at 1,600 to 2,400 calories for women and 2,000 to 4,000 calories for men per day, advises Tufts. Use your Basic Metabolic Rate, or BMR, to figure out how many calories you need to add on top of that.

Basic Metabolic Rate

As if weight gain was not hard enough, now there is math involved. To figure out how many calories you need to add in order to gain weight, learn how to figure out how many calories your body burns when it is at rest, advises the International Sports Sciences Association. This looks a bit complicated at first, but it makes sense once you break it down.

The formula for calculating BMR is:

  • Male BMR = 66 + (13.7 x weight in kilograms) + (5 x height in centimeters) - (6.8 x age)
  • Female BMR = 655 + (9.6 x weight in kg) + (1.7 x height in cm) - 4.7 x age

To calculate the BMR of a 100-pound woman who is 5 feet, 6 inches tall, 35 years old and moderately active, you would convert her weight to 45.36 kilograms and her height to 168 centimeters. Do the math to get a formula of 1,090.46 + 285.60 - 164.5 to get a BMR of 1,211.56. That is the minimum number of calories she needs to function at rest. Being moderately active, ISSA says, she would multiply that total by 1.6 for a total of 1,938.5. Add 500 calories daily to gain 1 pound per week, and she needs a total of 2,438.5 calories per day.




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