<i>If you&#x27;re gaining weight, it means you&#x27;re eating more than your body can burn, so you need to eat less.</i><p>Or your body is skipping the usable energy stage completely for some foods and storing them as fat directly without it ever having the chance to be used. Then some of the food you eat makes you gain weight regardless of the amount of activity you do - you just run out of energy <i>and</i> get fat.<p>The mistake you&#x27;re making is assuming that humans are perfect machines for turning food in to energy, and simple mechanics means extra energy is stored as fat. It&#x27;s <i>far</i> more complex than that.