Weight gain is usually something people try to avoid. In America, obesity is a much bigger problem than being underweight! But for many individuals, the opposite is true; they can lose weight without even trying and can’t maintain a healthy weight for very long.

Unfortunately, being underweight can be just as bad as being overweight. But just like there are ways to healthily lose weight, there are also ways to gain weight safely without risking eating disorders or damage to the gastrointestinal tract.  

When is a Person Underweight?

According to BMI ranges, anyone with a BMI of 18.5 is considered underweight. But we mostly hear about people who are overweight or obese these days.

BMI is a great metric to use to determine whether you or someone you know is underweight or overweight since it compares their weightto their height. For example, a person who weighs 150 pounds might be overweight if they are very short but they might be underweight if they are very tall. You can calculate your BMI by visiting this site.

While being underweight isn’t necessarily as bad as being overweight, it is still not an ideal body weight status. Healthy individuals are neither underweight or overweight. Furthermore, it can be tough for underweight individuals to gain weight safely, especially if they want to pack on weight quickly.

Low Body Weight Causes and Symptoms

People can be underweight for all kinds of reasons, just like they can be overweight because of more than one origin. Some of the most common causes of low body weight include:

  • Genetics. Some people are just genetically skinnier and lighter than others.
  • Poor or unhealthy eating habits. People need to eat enough calories every day to maintain weight homeostasis. Furthermore, if individuals eat enough but don’t get enough nutrients or vitamins, their bodies may not be able to pack on and keep weight.
  • Chronic illnesses, which can sap away the body’s energy and nutrients.
  • Excessive physical activity as seen in athletes. Burning too many calories without replacing them can lead to weight loss.
  • Mental illness or disorders, like depression, anxiety, or bulimia.

Underweight people often experience biological problems and symptoms. They may also be more susceptible to disorders or long-term conditions, including:

  • Osteoporosis.
  • Problems with their skin, teeth, or hair.
  • A greater risk of getting sick since the body’s immune system will be weakened.
  • Fatigue and exhaustion.
  • Anemia, as underweight individuals have lower than average blood counts.
  • Irregular periods if female.
  • Slow impaired growth.

Ways to Gain Weight Healthily

For underweight individuals, gaining weight is important. But it’s also crucial to gain weight healthily and carefully. Gaining weight too quickly could lead to the development of new disorders, unhealthy eating habits, or even injuries.

With that in mind, let’s take a look at some healthy ways to gain weight.

Add Nutrient-Dense Foods to Your Diet

For starters, consider adding some nutrient-dense food to your diet. Nutrient-dense foods including cheese, coconut and olive oils, nuts, and fatty fish can do wonders for giving your body the vitamins and minerals it needs to build new tissue. Nutrient-dense foods are also an excellent starting place when creating a new, long-term healthy diet for your lifestyle.

Naturally, you should avoid fast food, junk food, and any processed foods you can. These foods may be calorie-dense but lack the nutritional content necessary to gain weight in a healthy and sustainable way.

We also recommend you avoid refined carbohydrates. These can be effective fuel for the body, but they can also help you gain fat rather than muscle mass. Instead, try to eat healthy fats and other alternative foods to satisfy your appetite like:

  • Avocados.
  • Oils like coconut oil.
  • Nuts, Peanut Butter, nut butter.
  • Smoothies and protein shakes.
  • Salads.
  • High-fat dairy, Whole milk, full-fat yogurt.
  • Whole-grain bread, brown rice, pasta,, fruits (berries) and vegetables, dairy products, cheese, sweet potatoes.
  • Dark Chocolate.
  • Bran muffins and granola bars.
  • High-quality, non-GMO meats .

You should only add complex carbohydrates under the recommendation of your doctor and if your cholesterol, blood pressure, and blood sugar levels are stable. Good choices for carbs include quinoa, whole grains, and organic rice.

Eat Regularly

You should also eat regularly. Try to eat three times per day at a minimum, and with manageable meal sizes. Breaking up your meals into three parts prevents you from overheating and damaging your gastrointestinal tract in the process.

Even better, eating several distinct meals helps you plan out what you’re going to eat and lets you count your calories. That way, you won’t overeat in the process of trying to gain weight.

HIIT Training and Exercise

HIIT or high-intensity interval training is one of the best ways to add muscle and increase your cardiovascular health. These types of training techniques are also ideal for individuals who don’t feel comfortable spending hours a day at the gym.

Fortunately, you can check out HIIT training guides and techniques right on Dr. Livingood’s site. Get started with our exercise routines and you’ll gain weight as muscle instead of fat. You’ll also feel better the longer you stick with the plan. 

Reduce Your Stress Levels

Stress can make it easier for the body to shed weight. Therefore, you can gain weight and keep a healthy BMI if you reduce your stress levels for meditation, get plenty of sleep, and eliminate stressful factors from your life.

Whether that means taking a job, cutting out toxic people, or something else, do everything you can to reduce your stress levels and you’ll feel better in no time at all.

Speak to a Doctor About Medical Causes

Lastly, consider speaking with a medical professional if you suspect your weight loss or chronic underweight status is because of one or more medical conditions. They’ll be able to diagnose you for any long-term or chronic problems and provide medication if needed.


In the end, you can and should gain weight healthily if you are underweight or are constantly losing weight without meaning to. Try out several of the tips above and remember to check out our HIIT training videos and techniques. 


Adult BMI Calculator | Healthy Weight, Nutrition, and Physical Activity | CDC

FastStats – Overweight Prevalence | CDC

11.4: Health Risks of Overweight and Underweight | LibreTexts