What if we could move beyond a “one-size-fits-all” way of losing weight? Scientists are finally accepting that intermittent fasting, as performed on Isagenix-style Cleanse Days, can be an effective dietary method for weight loss and weight management.
It’s easy to dismiss new diet trends that come and go. Fad diets rarely have staying power once subjected to rigorous randomized controlled studies, and they rarely achieve scientific validation with clinically meaningful results.
Among the medical community, the term clinically meaningful as it refers to weight loss is a 5-10 percent reduction in bodyweight (1, 2). To achieve this clinically meaningful weight loss, the traditional recommendation is continuous energy restriction of about 600 calories per day (3). This is as part of a multicomponent weight management program that includes diet and physical activity.
It’s also well known that most people who lose 5-10 percent of the bodyweight end up gaining it back (4). The majority end up regaining the weight they’ve lost within months. For this reason, scientists have often questioned the effectiveness of continuous calorie restriction through regular dieting.
A newly published systemic review and meta-analysis reported that short-term periods of intermittent fasting on a weekly basis are just as effective for clinically meaningful weight loss as compared to standard diet restriction (1).
Impressive Weight-loss Results
In this analysis, only randomized controlled trials of 12 weeks or greater in adults who were overweight and obese were included. The authors pooled together five studies and analyzed multiple outcomes including weight loss and adherence. Together the intermittent fasting interventions achieved an impressive average weight loss of 23.6 to 38.8 pounds.
While the energy intake and fasting periods in the five primary studies varied, the weight loss achieved was clinically meaningful.
The authors noted that moving beyond a “one-size-fits-all” approach to weight management could maximize weight loss and compliance. Giving people the option of varying how they approach weight loss can prolong weight loss by maximizing dietary compliance and could help prevent weight loss plateaus and weight regain.
Intermittent fasting could also help to overcome weight regain. Typical weight regain is thought to be related to something the body goes through called “adaptive thermogenesis” as a result of reduced calorie intake along with changes in appetite. But the research suggests that regain could be avoided through regular periods of fasting incorporated both into weight loss and weight maintenance programs.
Isagenix Intermittent Fasting
The Isagenix System incorporates intermittent fasting in the form of Cleanse Days and has been found to help keep the weight off in a long-term study (5).
The study was designed to include two phases: a 12-week “weight loss” phase with use of Isagenix products followed by a 52-week “weight maintenance” phase where subjects diverted into two groups who either consumed Isagenix products or returned to a traditional heart-healthy diet. After the subjects lost an average of 10 percent of their total body weight, along with nearly 20 percent body fat and 33 percent visceral fat during the first phase, the subjects who continued to use Isagenix products maintained significantly lower body weight and body fat.
In addition, the participants who kept the weight off long term had incorporated intermittent fasting as one or two Cleanse Days per month. These limited-food days help to reset appetite and offer a person the ability to stay on track with calorie-control goals over time.
Harris L, McGarty A, Hutchison L et al. Short-term intermittent energy restriction interventions for weight management: a systematic review and meta-analysis. Obes Rev. 2017 Oct 4.
National Institute for Health and Clinical Excellence (NICE). Obesity: identification, assessment and management of overweight and obesity in children, young people and adults. CG189. NICE, UK London. 2014.
Kushner RF, Ryan DH. Assessment and lifestyle management of patients with obesity: clinical recommendations from systematic reviews. JAMA. 2014 Sep 3;312(9):943-52.
Loveman E, Frampton GK, Shepherd J, et al. The clinical effectiveness and cost-effectiveness of long-term weight management schemes for adults: a systematic review. Health Technol Assess. 2011 Jan;15(2):1-182.
Arciero PJ, Edmonds R, He F et al. Protein-Pacing Caloric-Restriction Enhances Body Composition Similarly in Obese Men and Women during Weight Loss and Sustains Efficacy during Long-Term Weight Maintenance. Nutrients. 2016 Jul 30;8(8).