Why are high levels of insulin bad for weight loss? Jason Fung, MD, a nephrologist (kidney specialist) who specialises in obesity told POPSUGAR that the issue with weight gain isn't too many calories, it's "too much insulin." Eating sugar causes insulin levels to rise, which signals your body to store fat.
"Refined sugar overwhelms our natural hormonal treatment of sugar and the body (through insulin spikes) takes the excess sugar and parks it into the abdomen," Dr. Tarman explained. That's why insulin is known as the 'fat-storing hormone," she said.
Fat stored inside the abdomen beneath your abdominal muscles around your organs is known as visceral fat. This type of fat can not only lead to inflammation, Hodges said, but Dr. Tarman added that visceral fat "is the visual warning of illnesses such as diabetes and heart disease to come." Eating too much sugar and gaining visceral fat can create what doctors call metabolic syndrome, which could not only lead to the diseases previously mentioned, but also high cholesterol, Alzheimer's, and cancer, Dr. Tarman explained.