The phrase "regain weight" is correct and usable in written English.
You can use it to describe someone or something that is putting on weight after a period of losing it. For example: After months of watching his diet and exercising, John was finally able to regain weight and return to a healthy weight range.
He had surgery, but was never able to regain weight.
But some of them are going to regain weight.
Over time, the pouch stretches, and if people do not exert some self-control, they will regain weight.
The laparoscopic gastric-band procedure worked for Roberts for about a year, but then he began to regain weight.
Those who stuck with either of the exercise programs regained less weight than those who didn't exercise and, even more striking, did not regain weight around their middles.
"Most people simply regain weight, no matter what diet they are on," said the lead author, Dr. Daniela Jakubowicz of Tel Aviv University.
The scientists observed that the changes to the gut microbiome brought about by obesity persisted for five times as long as the actual period spent dieting and predisposed the mice to rapidly regain weight.
The king was in hospital in January, exercising 30 minutes a day on a stationary bicycle and passing a medicine ball with a physical therapist to build up strength and regain weight.
Royal Family: King, Crown Prince, Entourages 7. (S) Regarding King Bhumibol's health, Prem indicated that the King was exercising 30 minutes a day on a stationary bicycle at Siriraj Hospital and passing a medicine ball with a physical therapist to build up strength and regain weight.
For one thing, the body reacts to a weight-reduction diet as if it were starving and reduces the calories it burns, making it ever harder to lose without further caloric cutbacks and making it easier to regain weight with every dietary lapse.
But patients usually regain weight after they stop a diet, studies have repeatedly found.
