my cousin wants a diet sp

There is no secret to losing or gaining weight. To lose weight, eat less, exercise more. To gain weight, eat more, exercise less.
But it is also important what you eat, as well as how much!
Any diet not "balanced" will fail. An "all fruit diet" will fail; as will "all protein" or "all carbohydrates".
Losing more than one Pound in a week is dangerous.
Source:-
Nutrition Dept. St James' Hospital, Leeds.

Wow, the dead do roam the earth on Samhain, this is the third post I've seen brought back from the dead lol.

But to answer an old question, diet spells only work to assist, to motivate, they don't make you loose 5 dress sizes overnight by doing nothing. There's been a lot of scientific research into what causes some people to gain weight and others do not, but most can be solved with proper diet and exercise. If your cousin is on a healthy diet and exercise program but can't loose any weight, talk with a doctor.