Leroy Comrie, a city council member, will on Wednesday propose a bill that would prevent restaurants from giving away toys with meals containing more than 500 calories and 600mg of sodium.
The measure would effectively outlaw the Happy Meal, the boxed meal for children with a free toy that has been a staple of McDonalds's menu for more than 30 years, across the city.
Most varieties of Happy Meal exceed Mr Comrie's nutritional limits, which also demand that no more than 35 per cent of a meal's calorie content comes from fat. Some options contain about 1,000 calories.
The move by Mr Comrie, a Democrat from Queens, has raised eyebrows because he is thought to weigh about 24 stones himself. He has described himself as "an example" of poor eating habits.
"The City Council can empower parents by making it harder for the fast food industry to target children with predatory marketing techniques," he said.
McDonald's said the measure "would not solve childhood obesity".
A spokesman said: "We provide options for our customers and trust them to make the decisions that are right for their families. Politicians should too."
The New York Restaurant Association said the bill would "rob parents of choice while increasing the already burdensome regulation on local restaurant owners".