Q: I’m healthy, but I’m very thin and have trouble gaining weight. Any suggestions?
A: For some people, it’s just as challenging to put on pounds as it is for others to take them off. Just as some of us are prone to be plump, others are slated to be skinny—and there may be limits to how much weight they can gain.
As a rough estimate, it takes 500 extra calories a day to gain one pound a week. Certainly, you can gain weight by overeating cheeseburgers, fried chicken, French fries, bacon, cake, ice cream, and such, but this is likely to have adverse health effects.
Instead, eat higher-calorie versions of healthy foods, such as dense cereals instead of flake cereals, starchy vegetables (like corn, peas, potatoes, and winter squash) instead of watery vegetables (like lettuce and zucchini), and tuna packed in oil rather than water. Drink low-fat milk, or even whole milk, instead of water. Choose low-fat or whole-milk yogurt over nonfat (but still look for yogurts with little or no added sugar).
Another strategy is to eat more at each sitting—a bowl of soup instead of a cup, for instance, or an extra half sandwich. Include calorie-dense foods rich in healthy fats, like nuts, seeds, avocados, fatty fish, and olive oil.
You should also eat consistently. Aim for three or four meals plus one or two snacks a day. And eat balanced meals—avoid fad diets that push for extra protein or pitch protein supplements, for example. Lastly, do some strength training so that a greater portion of the weight you gain will be muscle, not fat.
If you have lost weight for unknown reasons, see your doctor to make sure there is no underlying medical cause.
This article first appeared in the UC Berkeley Wellness Letter.
Originally published November 2012; updated September 2019.
Also see The Secrets of Slim People.