Although sugary foods tend to be high in calories, it's the effect the sugar has on the body you need to worry about. Jason Fung, MD, a nephrologist (kidney specialist), explained that eating processed carbs and sugary foods such as cookies, crackers, pasta, and white bread spikes your insulin levels, which can cause weight gain. Keeping your insulin levels low will help reduce your overall body fat percentage, and that includes belly fat.
That's not all: when eating sugar elevates insulin levels, it blocks leptin (the hormone that signals to your body that you're full) and overloads your dopamine receptors, which leads to insatiable cravings, explained Susan Peirce Thompson, a psychology professor with a PhD in brain and cognitive sciences. In her book Bright Line Eating, she explained that this is why you eat cookie after cookie and still want more — eating sugar makes you crave it.
You don't need to ditch all carbs, though. Avoid refined carbs and go for complex carbs like whole grains, beans, veggies, and fruits. Registered dietitian Leslie Langevin, MS, author of The Anti-Inflammatory Kitchen Cookbook said, "They break down slowly in the body because of their high-fibre content and help to keep blood sugar levels steady since they are digested slower. They're also richer in nutrients than simple carbohydrates." Aim for three servings a day of whole grains, one to two of fruit, and one to two of legumes. Here's a list of the best carbs for weight loss.