The way you metabolise food strongly affects your subsequent food choices. A King’s College study gave over 1,000 participants a standardised breakfast, and found those who experienced big dips in blood sugar levels several hours after eating ended up feeling hungrier, eating sooner and consuming on average 312 more calories during the day than people with a more controlled blood sugar response. 1 That could lead to several pounds of weight gain each year. As well as genetics, your sleep, physical activity and food choices all affect metabolism, so don’t underestimate the effect these lifestyle choices have on your weight.