Sugar contains calories, thus, as with any food, if we eat too much of it we will gain weight. To maintain weight we need to burn off the same amount of calories as we are consuming from food, so if we eat more than we burn, weight gain will follow.
Sugar and sugar containing foods can be particularly problematic in this area as they are generally the types of foods we crave and may even become ‘addicted’ to, so it is easy to overeat them and therefore consume too many calories.
Sugar has recently been strongly linked to diabetes, obesity and weight gain, and there is no doubt that a high intake of sugar and sugar containing foods can contribute to weight gain. Reducing your sugar intake by eliminating added sugars and processed foods and drinks that are very sweet may be a good way to lose weight, control cravings and reduce risk of lifestyle diseases, however diets that eliminate any sugar containing food such as fruit is probably too extreme and is likely to put you at risk of deficiencies in other nutrients.