If you’ve been trying to lose weight and suspect your body’s working against you, you may be right, according to a University of Illinois study published in the journal Obesity. “When obese persons reduce their food intake too drastically, their bodies appear to resist their weight loss efforts. They may have to work harder and go slower in order to outsmart their brain chemistry,” said Gregory G. Freund, a professor in the U of I College of Medicine and a member of U of I’s Division of Nutritional Sciences. He particularly cautions against beginning a diet with a fast or cleansing day, which appears to trigger significant alterations in the immune system that work against weight loss. “Take smaller steps to start your weight loss and keep it going,” he said.