First, you want to determine if you are underweight or moderate weight for your age in height. Here is a free online calculator to help determine that. Then you should try to figure out your body fat percentage.
One way to measure your body fat percentage is using methods like skinfold calipers, bioelectrical impedance analysis (BIA), or DEXA scans. And if you or your doctor don’t have access to any of those then you can use an online calculator (not the most accurate) or try to eyeball it. Do some quick Google Image searches on body fat percentage and try to see what looks most like you.
Another great way to do this is to pay attention to how your clothes fit and where you tend to store fat on your body. If you notice that you have a higher concentration of fat around your midsection or other areas despite being generally thin, you might be skinny fat.
If you are in that grey area of being skinny fat, then it can be hard to figure out if you want to gain weight or lose weight. Here’s what to consider –