Isagenix markets a cleansing and fat-burning system you can purchase in a nine- or 30-day supply. Check with your doctor before starting this system because it isn't safe for everyone and hasn't been proven effective.
The Isagenix 30-day plan replaces two meals per day with shakes and has you eat a 400- to 600-calorie meal for your third meal. You also take their supplements, and two days per week in the first two weeks you drink their cleanse product instead of eating regular meals or drinking meal-replacement shakes. The ingredients of Isagenix include whey protein, fiber, enzymes and herbs, and the Natural Accelerator supplement also contains cayenne, green tea, cinnamon and ginseng, all of which the manufacturer claims assist fat burning. According to the manufacturer, these meal-replacement shakes and supplements improve energy, promote digestive regularity, increase endurance, encourage weight loss and help you maintain lean muscle mass.
An Isagenix-funded study published in Nutrition & Metabolism in 2012 found that over an eight-week period, people who used Isagenix meal-replacement shakes as part of an intermittent fasting and calorie-restriction diet lost 2.2 pounds more than those who followed a similar diet using regular food. However, according to a 2012 article published on the Science-Based Medicine website, this study wasn't well-designed, and Isagenix paid to get it published in the journal. The author of the website article, Dr. Harriet Hall, also noted that there were inconsistencies in the numbers listed in the results, potentially making the conclusions unreliable.