No foodstuff in itself is fattening. It is when energy output (physical exercise) is less than input (food intake) that one is inclined to gain weight. Nevertheless, like all fatty matter, butter has a high energy value: 10 g of butter will supply about 75 kcal, just like the same amount of margarine, and a table spoon of oil will supply 125 kcal. Everything therefore is a question of quantity.

To be noted: research has shown that saturated fatty acids (along with unsaturated omega 3) are only moderate generators of body fat compared to omega 6.