Foods that will increase my weight?

Weight is a matter..: ...Of calories in vs. Calories out. If you eat more calories than you burn, you gain weight. That said, do it in a healthy way; you do yourself no favors by trying to gain weight by eating cookies. Also, discuss with your doctor whether you are actually at a healthy weight or not. If your doctor says your weight is good, it is unwise to continue trying to gain.

Calorie dense: High fat, high sugar, low volume, low water content, low fiber, alcohol, concentrated sweets. Those are good for starters. Big portions, sugary beverages. Physical inactivity. All the above factors will increase weight, can cause obesity (among other factors). If trying to gain weight, increase good quality protein, but not low fat items; aim for "good" fats, like oils, avocado, not trans fats. Add a smoothie daily, or a piece of chocolate.

Calories, weight: If calories in equals calories out, then your weight will remain the same. To lose weight, there must be an intake caloric deficit and/or an output caloric expenditure (calories burned). Therefore to lose weight eat less and exercise more. The latter is very important because of the health benefits and muscle development. Remember muscle mass uses more energy.