In middle-aged women with metabolic syndrome risk factors, consuming 7.9 grams of resistant starch daily for 8 weeks is associated with a mean increase of 40 mg/dL in serum triglycerides and a 1.0 kg increase in body weight, suggesting that high resistant starch intake may promote hepatic lipogenesis and adiposity in this population despite no change in total caloric intake.

When resistant starch reaches the colon, it feeds a type of gut bacteria called Veillonella, which turns it into acetate and propionate. These molecules travel to the liver and turn on a switch called SREBP-1 that tells liver cells to make more fat. The extra fat enters the bloodstream as triglycerides and gets stored in fat tissue, increasing body weight even when calorie intake stays the same.