Saturday, July 21, 2012
Does Juicing for Weight Loss Really Work?
Before explaining how juicing for weight loss may work, I think it's a good idea to explain how any diet for weight loss, more specifically for fat loss (it's possible to lose weight without losing fat), actually works. The principle isn't all that complicated. Fat cells tend not to absorb fat and release fat to be burned elsewhere in the body at the same time.
And it turns out that what determines whether fat cells are absorbing fatty acids for storage or releasing fatty acids to be burned as fuel depends on the activity of two hormones known as lipoprotein protease, or LPL, and hormone sensitive lipase, or HPL.
LPL helps transport fatty acids into fat cells so they can be transformed into triglycerides for storage. Triglycerides stay parked in fat cells until they are broken down into fatty acids once again by HPL.
LPL is activated by insulin. When insulin levels are higher, LPL is more active than HPO and triglycerides stay inside fat cells--sometimes even if you are consuming fewer calories than your body burns. Your body just gets those calories from places other than your fat cells, like your muscles.
When insulin levels are lower, HPL is more active than LPL and triglycerides are broken down into molecules that can escape your body fat. When this happens, the fatty acids released by your fat cells are used for fuel--sometimes even if you are consuming more calories than your body burns.
So what does juicing have to do with all of this?
Juices contain a form of carbohydrate called fructose. Usually fructose is decried as the enemy of all things healthful and holy, but up to about 50 grams (one tall glass of juice a day, or, better, three half-cup servings of juice a day) can be stored without insulin.
And that means that you can enjoy the energy boost for small amounts of juice as well as getting the antioxidants and potassium without interfering with the fat-burning benefits of eating less.
And, sorry, you still have to eat less to lose weight. There are no miracle weight loss juices or miracle weight loss foods or miracle weight loss pills, either. But if you are going to snack between your reduced-calorie meals, small amounts of juice, up to 4 fluid ounces (120 ml) every couple of hours, are a great way to keep up your energy without interfering with fat burning.
I know this goes against both the calories in-calories out concepts of weight loss and the Gary Taubes fructose-is-of-the-Devil school of weight loss. But try it. You do the hard work of losing weight by eating less. But fruit juices can help you keep your energy so you stay focused and stick to your plan.
Photo credit: Midori, via Wikimedia Commons.