New UCSF Study Suggests Intermittent Fasting Doesn’t Help You Lose Weight

A new study coming out of University of California, San Francisco has suggested that conventional wisdom that intermittent fasting can help with weight loss isn’t supported by scientific evidence.

The new study was pioneered by Dr. Ethan Weiss, an American cardiologist who has been studying the effects of intermittent fasting on the body for seven years. Recent trends in sports nutrition and health — such as juice cleanses and highly restrictive paleo diets — have relied on the assumption that intermittent fasting and restriction nutritional intake at least temporarily will help you lose weight. However, a study conducted by Weiss disproves this theory, and shows that intermittent fasting actually has no lasting effect on body weight.

Weiss personally experimented with intermittent fasting and started losing weight initially. This breakthrough led him to initiate a clinical trial through UCSF to determine the long-term effects of intermittent fasting on weight loss. You can read the full overview of his clinical trial and how it was conducted here if you want to really delve into the research science behind it.

The first group of subjects was told to fast for an eight-hour window each day, while the control group was allowed to eat normally and with snacks. The results were that the fasting group lost an average of 2 pounds over a 12 week period, while the control group lost an average of 1.5 pounds. There was no statistical difference between how much weight was lost between the two groups.

Intermittent fasting has been popularized through Instagram and other forms of social media. Many influencers and actors have credited the practice with helping them lose weight and get into better shape. Further study of the initial group also revealed that this is a myth; the group of subjects who engaged in fasting actually lost more muscle mass than the control group, meaning they weren’t even losing more fat, just muscle. Fasting actually increased the ratio of fat to muscle in their body.

Intermittent fasting is just one of the many unchecked fitness tips that has been circulating on the internet for years. The truth is, a lot of what you see reported, especially on social media, is just designed to get you to buy into a certain product or lifestyle. The only way to be sure that what you’re doing is correct is to do the research yourself and consult with actual scientists and experts who can confirm their research through rigorously vetted studies. We hope everyone out there is being safe about their fitness practices and making responsible choices about their nutrition.

Instead of intermittent fasting for weight loss, try out a healthier diet or more exercise. Restricting fried foods like fast food and soda can have a huge impact not only on your physical fitness and weight but on the health of your heart, which can ultimately lead to a longer life.