Aim for 300 Minutes of Exercisebr a Week to Lose Weight, Study Says.br Normally, when a person works out,br their appetite increases in an attemptbr to compensate for lost calories. .br This makes weight loss difficultbr for people who are not strictlybr monitoring their food intake. .br A study published in ‘Medicine & Sciencebr in Sports & Exercise’ has found the br “inflection point” where weight loss is possible.br The study, conducted by Kyle Flack, anbr assistant professor at the University of Kentucky,br involved 44 sedentary, overweight men and women. .br Half of the participants were asked tobr exercise twice a week for at least 90 minutes. .br Their goal was to burn aboutbr 1,500 total calories a week.br The other half was instructed to exercisebr six times a week for about 40 to 60 minutes,br or around 300 minutes a week.br Their weekly goal was to burn atbr least 3,000 total calories. .br After 12 weeks, Flack found that only thosebr in the second group lost weight. .br He also found changes in the second group’sbr levels of leptin, a hormone that reduces appetite.br Flack hypothesized that the alterationbr enabled them to better regulate theirbr desire to eat and therefore maintain abr weight-shedding calorie deficit.