I am a member of LA Fitness in Marietta, Georgia and I saw an advertisement about you accepting email questions. I was wondering what you think about 16-8 fasting diet. My doctor told me about it. I’ve read a lot about it but it appears it’s just for obese people which I’m not. I need to lose about 10 to 15 pounds. Any advice would be much appreciated.
– Donna G.
From what I know of this variation of increasingly popular intermittent fasting, the 16-8 approach is strictly time based, with eating condensed into 8 hours after a 16 hour fast. Periodic fasting (time restricted feeding) allows one to forgo traditional calorie-counting in an attempt to reduce overall caloric intake. Successful long-term weight loss methods also incorporate routine food intake recording, weight monitoring and 150 minutes per week of moderate intensity exercise.
Current articles show the following about intermittent fasting… In a small New Zealand study1 of 37 subjects with type 2 diabetes and obesity, 5:2 fasting over 12 weeks improved weight, HgA1C, fasting glucose, and reduced need for medication, though there were more hypoglycemic events. An even smaller pilot study2 on obese individuals following 16-8 fasting over 12 weeks resulted in lower systolic blood pressure, reduced daily intake by approximately 340 calories, and nearly 3% loss of body weight compared to controls. A Registered Dietitian’s review3 concluded that “There’s clear disagreement even among researchers on the benefits of fasting and which type of fasting would be best for which individuals,” yet “Fasting may be a viable weight loss option for obese individuals who can’t stick to a daily calorie restriction.”
The effect on normal-weight individuals is not known. See our previous answer to “Will intermittent fasting help me lose weight?” by clicking here.
- Intermittent fasting in Type 2 diabetes mellitus and the risk of hypoglycaemia: a randomized control trial. BT Corley, et al. February 2018. Diabetic Medicine. https://doi.org/10.1111/dme.13595
- Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study. K Gabel et al. June 2018 Nutrition and Healthy Aging 4(4): 345-353.
- Fasting Regimens for Weight Loss. Densie Webb. February 2018. Today’s Dietitian 20(2): 34
– Debbie J., MS, RD
This article should not replace any exercise program or restrictions, any dietary supplements or restrictions, or any other medical recommendations from your primary care physician. Before starting any exercise program or diet, make sure it is approved by your doctor.
Some questions have been edited for length and/or clarity.