The Most Significant Causes of Weight Gain and Obesity

Refined Sugar

Processed or refined sugar may arguably be the most predominant cause of obesity worldwide. Sugar is made up of half glucose and half fructose, which have been shown to elevate insulin levels when eaten in excess amounts. Sugar may also cause leptin resistance and contributes to fat storage as it is high in calories and low in nutrients. It should be noted the sugar found in fruit is perfectly healthy and does not increase insulin levels like refined sugars do. One study even shows when eaten with high glycemic foods, such as white bread, berries have a protective effect that may even reduce insulin spikes.

Genetics

Research shows some individuals are simply genetically prone to being overweight. One study looked at the differences between genetics and long-term overfeeding in twelve pairs of young adult monozygotic twins. The twins were overfed by approximately one thousand calories per day for six weeks. Each twin was examined for changes in body composition, fat mass, percentage of fat, and topography of fat distribution. Results showed each set of twins exhibited different regional fat distribution and amount of abdominal fat, meaning genetics may govern how the body stores energy as either fat or lean tissue, at least in part.