A study published in The British Medical Journal, one of the world’s oldest general medical journals, reveals that substituting refined grains, foods with high added sugar, and starchy vegetables like potatoes, peas, and corn with whole grains, fruits, and non-starchy vegetables can decelerate weight gain as individuals age:

an increase in dietary glycemic index, glycemic load, and amounts of starch, added sugars, refined grains, and starchy vegetables are associated with greater weight gain in mid-life. In contrast, an increase in amounts of fiber, whole grains, fruit, and non-starchy vegetables was associated with less weight gain. These findings support the potential importance of carbohydrate quality and source for long term weight control.