Why We Gain Weight, and How to Get Slim

Last updated: 26 October 2026

“Eat less and exercise more” is the advice most of us grew up with. But research increasingly shows that this view of calories in versus calories out is too simple.

Two very different ideas

Compare these two statements: “People eat a lot, so they get fat” and “People are getting fat, so they eat a lot.” The first blames greed and lack of self-control. The second suggests that overeating is a result of the body wanting to store fat, not the cause of it.

It is a concept that challenges conventional nutrition advice. When your body is in fat-storing mode, it keeps sending signals to eat more.

Signs your body is in fat-storing mode

• You feel hungry most of the time and rarely feel full or satisfied.
• You gain weight easily, or find it very hard to lose.

What you can do about it

We cannot change our genes, but we can change what we eat. The approach below is based on a diet published by a team of British physicians led by endocrinologist Raymond Greene. And no, it is not a starvation diet.

Cut back on fattening carbohydrates:

• Bread and anything made with flour
• Breakfast cereals
• Potatoes
• Foods high in sugar
• Sweets and desserts

Enjoy freely:

• Meat, fish and poultry
• Green vegetables
• Eggs
• Cheese
• Fruit, except bananas and grapes

Give it a try for just three days and notice how your hunger and energy change.