Fasting for weight loss is one of the many new “get-fit-quick” schemes going around. To say the least, it is a dangerous one.
I recently saw a video of a self-proclaimed fitness expert explaining that lions are muscular because they practice fasting. Therefore, he thinks humans should also practice fasting to become lean and muscular.
How is it reasonable to compare the eating habits of lions and human adults? It’s not. Aside from differences in DNA, lions and humans have different lifestyles. For example, male lions sleep an average of 20 hours per day. On the other hand, human adults sleep 7 to 9 hours on average. Humans are rational beings and have an average life expectancy of about 80 years (not 10-14 years like lions).
So what do experts say about fasting for weight loss? The experts agree: fasting is not a healthy weight loss tool and a deceptive form of dieting.
“The appeal is that [fasting] is quick, but it is quick fluid loss, not substantial weight loss,” says Madelyn Fernstrom, PhD, CNS, founder and director of the University of Pittsburgh Medical Center’s Weight Loss Management Center.
“If it’s easy off, it will come back quickly” once you stop fasting and resume your normal eating habits.(1)
Even some proponents of fasting for other medical purposes do not support fasting for weight loss. Some say it can actually make weight problems worse.
“Fasting is not a weight loss tool. Fasting slows your metabolic rate down so your diet from before the fast is even more fattening after you fast,” says Joel Fuhrman MD, author of Eat to Live: The Revolutionary Plan for Fast and Sustained Weight Loss and Fasting and Eating for Health.
In fact, research reveals that fasting for weight loss carries additional health risks as well, and it has negative side effects.
Occasional fasting may be fine for healthy adults, yet “it can be quite dangerous if you are not already eating a healthy diet, or if you’ve got liver or kidney problems, any kind of compromised immune system functioning, or are on medication — even Tylenol,” says Fuhrman, a family physician in Flemington, N.J..
Therefore, fasting is not a weight loss diet. It is definitely not a desirable way to get fit, improve your health, or build muscular strength. Overall, it is a dangerous proposition that could have irreversible negative effects on your health.
1. Seliger, Susan. “Is Fasting Healthy?” WebMD, WebMD, www.webmd.com/diet/features/is_fasting_healthy#1.