While many people struggle with too many pounds, there’s still a chunk of the population with the opposite problem. Being severely underweight can also be quite unhealthy. Whether you’re looking to build muscle mass or you’re simply too skinny, gaining weight isn’t something to take lightly — so to speak.

How Is “Underweight” Defined?

If your BMI (body mass index) is below 18.5, you’re technically considered underweight. Signs and symptoms can include fatigue, hair loss, and constant illness due to a weak immune system. Protruding veins or enlarged joints may be visible due to an inadequate layer of fat on your skin. In children, you may observe poor growth and physical development. Women may experience fertility issues or irregular menstrual cycles.

Making Good Decisions

You’ve determined that you need to gain a few pounds, but don’t reach for the donuts just yet. Eating the wrong things and gaining weight too quickly can have many negative results, including high blood pressure, stretch marks, and sleeping issues. Think with your head, not with your stomach.

Increased sugar intake is necessary to gain weight, but you should seek natural sources of healthy sugar such as beets, fruit, and wholesome carb-rich bread. Taking in more fat is also critical, but make sure to avoid processed oils and trans fats in favor of avocados, nuts, seeds, coconut oil, and similar sources of beneficial high-fat foods.

Proper Documentation

Slow and steady weight gain is the healthiest strategy, and counting calories and fat intake are key. Using Lifesum’s calories and carb counter is an easy way to track your intake. When using a calorie counter app, keep a few things in mind. For example, portion size is something that often trips people up. Pasta usually has portion sizes listed by weight. Who weighs their pasta before cooking it, though? In general, a portion is about a cup and pasta usually doubles in size when it’s cooked.

Dining out used to be a huge challenge when counting calories, but fortunately, things have drastically changed in this regard. Coffee shops, restaurants, and even gas station fast food stands are now posting calorie content for their offerings. If it’s not posted, ask — there’s usually a sheet with all the data you need that’s handed out upon request.


For healthy weight gain, a regular exercise regimen is key. After all, you probably prefer muscle mass over stored fat. Just be sure to subtract the calories burned during workouts from your daily caloric intake. This can also be tricky, however, since different forms of exercise burn calories at vastly different rates. Don’t forget those everyday tasks when crunching your numbers! Cleaning your house, mowing the lawn, and other tasks that involve vigorous movement should all be considered exercise.

Thanks to the advanced technology in everything from smartphone apps to cardio equipment that measures your heart rate and calorie burn automatically, responsible weight gain is easier than ever. By leveraging the tools at your disposal, you can ensure that you’re building yourself up instead of blowing yourself up.

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Lifesum App


Based on 222,204 customer reviews.

Last updated: 2018-12-05. To leave a review, visit App Store or Google Play.

5 out of 5 stars

I absolutely loooove this app to track my macros. I’ve been doing it for a month and it has helped so much with staying on track. I also have an Apple Watch so it helps showing the calories I’ve burned as well. Absolutely love it and highly recommend it!! *****

5 out of 5 stars

This app is so much more than just counting calories, it also keeps in mind carbs, protein and fat while creating a personalized plan for you. The quiz at the beginning was so accurate and I’ve been eating so much better even after a couple days. Never thought I would be able to do it.

5 out of 5 stars

I can’t believe all the options in the food diary there are. Like, even generic food options from my local grocery store. I like the food plans it has an option, it has synced to my Fitbit, and has been user friendly. I’m excited to see how this plays out. I’m always a skeptic, but off to a great start!

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