Because all-slim diet plans take into account diet pills and no amount of carbohydrate all day which can result in harming a persons body if he doesn't follow his doctors advice and start this diet without his recommendation his weight will be lost but in long process his health will suffer.
Give your thesis a justification
Your thesis should not be a simple sentence, make it in a form that discussion arises from it which is duly justified by proper reasoning.
A strong thesis follows only one main idea
Never confuse a reader given him more than one idea, try to focus your thesis statement on one main idea and work on it the whole way.
Make your thesis specific
Try to make your thesis specific and to the point, don’t let your point stray in the the opposite direction this will help in making your essay manageable.