Carbohydrates are a key element of nutrition in their natural forms. However the food industry has broken these down to such a simple form that they create a metabolic shift that creates to rapid fat storage.
When food is absorbed in the intestine, the blood sugar bumps up, insulin (the storage hormone) responds, and the calories are stored in the fat cells. The more often the insulin level is elevated, the more we stay in storage mode. Natural carbohydrates take some time to be broken down and absorbed. But the ones that are highly processed, particularly when they contain white flour and white sugar, they are absorbed very very quickly causing a more pronounced rise in sugar, then insulin, then off to the fat cells they go.
One way to avoid that rapid absorption is to avoid those very refined carbohydrates. The newer GLP agonist injections, weight loss and diabetes medications, such as semaglutide (wegovy/ozempic) and tirzepatide (mounjaro/zepbound) also can slow down that rapid absorption by slowing down how quickly food is emptied from the stomach.
Key is looking at labels. Most foods that are not refrigerated, frozen, or canned in their natural form contain sugar as a preservative. And if you are dieting, shop the perimeter of the store, avoiding the aisles.