A new study says there's no such thing as the "best" diet.
Stanford researchers followed 600 people assigned to a variety of diets.
After 12 months, those following low-carbohydrate or low-fat lost about the same weight - about 12 pounds.
Contrary to some diet claims, they also found a person's genetic makeup doesn't seem to affect whether a certain type of diet will work.
But overall what did make a difference was healthy eating.
They found people who ate less sugar, fewer processed foods and more vegetables lost the most weight.
Here's more from Stanford University.