A thesis statement should tell the reader your belief about something and demonstrate that you have evidence to support that belief.
Your thesis statement could say that you believe "eating disorders is a worldwide problem." But that's not a very strong opinion.
That is, you realize you've bitten off more than you can chew.
You can always narrow the focus of your topic to present your argument more convincingly and fit within your assignment guidelines.
The world is fickle, and the number of things you can describe and discuss in your school essay is always growing.
Students write about artificial intelligence, the problems of social networks, and video game addiction, issues that are becoming more pressing with each day.
Then you would add what type of problem it is (is it psychological, neurological, chemical? A good thesis statement needs to present your opinion in a convincing manner, encourage the reader to continue reading for your evidence, and provide a guide for the reader to know where your paper is going (how your argument will be presented).
Do not be discouraged if, once you begin your research, you realize that your original thesis statement was too broad a topic.
One of the strengths of studying eating disorders such as compulsive over-eating or anorexia nervosa from a purely biological perspective is that eating is a biological phenomenon that impacts the body and the mind.
Starvation, as observed in non-anorexic subjects that have been forcibly starved, produces psychological effects that might be assumed to be the result of personal pathology, not simply restricting one's diet-such as depression, an obsession with food, obsessive-compulsive behavior, guilt, eating rituals, and a lack of sexual desire (Clark, 2000).