Wiktionary
n. Increase in weight, usually of a person or animal.
Wikipedia
Weight gain is an increase in body weight. This can involve an increase in muscle mass, fat deposits, excess fluids such as water or other factors. Weight gain can be a symptom of a serious medical condition.
Usage examples of "weight gain".
She could have eaten as much again as had been on her plate, but Melfane had announced her strict intention to limit her weight gain.
The girl had been eating ravenously, making up for her long hunger, and Iza thought she could notice a weight gain already.
Her prohibition of his favorite blend rose from her theory that its hidden calories and fatty oils were responsible for the five-pound weight gain and slightly elevated cholesterol level revealed by his latest routine checkup.
In her campaign to keep her weight gain to a minimum, anorexia was her ally.
What you need is a systematic weight gain program: eating (lots of carbohydrates, a fair amount of protein, no junk) plus weight lifting, with an emphasis on upper body exercises -- six to eight repetitions per exercise with heavy weights.
That way she could attribute her expanding abdomen to weight gain rather than pregnancy.
I checked my extremities but found no evidence of massive overnight weight gain.
Had some ImpSec analyst calculated his weight gain against this date?
Tanalasta's face had seemed weary and tired, but also much rounder than he remembered, with a certain heaviness below the jawline that bespoke a considerable weight gain.