So much nutrition and diet advice is aimed at losing weight, but if you're too thin, you may be at a loss on how to gain weight. Instead of trying to gorge yourself with masses of sweet, rich, or fatty foods, choose high-calorie foods that provide energy and build muscle mass without all of the unhealthy fats that can cause you harm.﻿﻿

How to Get Started

The weight gain equation is pretty simple: consume more calories than you burn. If you have a high metabolism or exercise vigorously, you may be placing yourself at a calorie deficit if don't eat to meet to your need.

If you don't have a clue how many calories you burn per day, use an online calorie calculator to figure that out. Next, build a diet plan that exceeds that value.

The 3,500 calorie per pound rule has been used to set up diets. Based on the rule, is believed that reducing 500 calories per day is thought to result in a pound of fat loss or gain each week. But it's not clear how accurate the 3500 calorie per pound rule actually is or how well it will work for setting up a weight-gaining diet.﻿﻿

Adding roughly 500 calories each and every day—ideally with energy-dense foods and snacks—should give you the extra calories you need to increase your weight.

To make the plan work, eat smaller, more frequent meals throughout the day and use toppings (gravies, chopped nuts, ranch dressing) to add calories without bulk. To get your weight gain strategy started, here are eight nutritious, high-calorie (but still healthy) foods to add to your list: