stay on a diet meaning

• [American slang]
  Go to on a diet

• diet:    Noun: diet &n ...
• on a diet:    [American idiom]tr ...
• stay:    Verb: stay &n ...

Examples

1. He had to stay on a diet to stay at that weight.
2. "I was losing weight for a movie and can't stay on a diet, so I smoke.
3. The Microwave Bank not only cooks food, but it also provides bank balances, pays bills, creates shopping lists and helps you stay on a diet.
4. Defining a turning point in a game decided by 52 points may be as pointless as trying to stay on a diet at the State Fair of Texas.
5. Most people try to stay on a diet of total carbohydrates, but they skimp on protein, " she said, adding that athletes typically need a little more protein than sedentary adults.