One of the things we love most about our jobs is that people ask us questions about health that get us scratching our heads. We’ve heard some crazy health claims over the years. We have also heard some that sound plausible. And, some come back every year. One that crops up with chilly weather is that shivering is a great way to lose weight.
Some studies have found that shivering converts white fat to brown fat and burns it away. One study in 2014 found that shivering for 15 minutes burned the same amount of fat as a full hour of moderate exercise. Shivering, like exercise, releases the hormone irisin that converts white fat to easily burned brown fat. Your body shakes to warm you, and that burns the fat. However, there is a lot more to it than that.
Shivering won’t give you the same long-term metabolic boost as exercise. And, researchers don’t believe it can lead to sustainable weight loss. Moreover, the study was very small, with just 10 participants under tightly controlled circumstances. The researchers had the volunteers lie under water-cooled blankets and slowly decreased the temperature until people shivered under 53.6-degree layers. With only 10 participants and it being so carefully controlled, it’s hard to tell if this has any real-world meaning.
Interested to see if it were the temperature or the vibration that was making the difference, researchers had a follow-up study. They had another small group of people stand on vibrating plates to see if their irisin levels increased. It did, but it had no impact on weight and immediately fell after they finished the study. They had another group of people do resistance training instead of shaking. They saw the same results: while they were working out, the hormone rose, but their baseline levels did not improve.
While some might say the practice of inducing shivering is harmless, others disagree. Aaron Cypess, a clinical investigator at the NIDDK, pointed out that shivering increases blood pressure. And, prolonged periods of shivering could lead to damaged blood vessels in the brain, heart and kidneys.
Paul Lee, an endocrinologist at the Garvan Institute of Medical Research, said, “Shivering causes stress and could harm the body, which explains why the human body has evolved mechanisms to turn on brown fat or to turn white fat into brown fat… While suggestions exist that long-term activation of brown fat could be beneficial to weight loss… this has yet to be proven.”
Bariatric surgeon Dr. Ramen Goel said, “I would not advise artificial shivering to lose weight. Brown fat is present in babies and goes off gradually. In adults it’s present in neck and back areas. Using this as an idea to induce calorie burn is still to be researched.”
Purposefully inducing shivering might not be the safest way to burn fat. Exercising normally and eating a healthy diet is probably still your best bet for losing weight in a safe and sustainable manner. But, this might make you feel less resentful of the cold this winter! When you’re walking outside, and a cold wind makes you shiver, that’s a tiny boost of fat burning in your day!