Yo-Yo Dieting is Good for You

A new and interesting study has found that yo-yo dieting is better than no dieting at all. It gives us all hope that trying is better than doing nothing while staying overweight. It gives heft to my (and Winston Churchill’s) strong belief to:

“NEVER, NEVER, NEVER GIVE UP!”

Here’s the scoop:

I was contacted by an ABC-7 producer who asked me to comment on the study – which seemed to turn our conventional wisdom that yo-yo’ing is bad for you – on its head. So I took a look. **

First, the study:

In a National Institutes of Health-funded study at Ohio University, researchers found that overweight, diabetic rats (yes, rats – so much like us, don’t you agree?) which yo-yo dieted, had better glucose levels, lower inflammation, and a 25% increased lifespan than overweight rats which stayed overweight. In fact, the yo-yo dieting rats lived about as long as the lean and healthy rats (there were three groups: obese rats which stayed obese, healthy and lean rats, and the yo-yo dieters).

“The new research shows that the simple act of gaining and losing weight does not seem detrimental to lifespan,” said the study’s lead author Edward List, a scientist at Ohio University’s Edison Biotechnology Institute.

While the study was conducted with rats, the implication for humans is huge and seems to back up some scientific data we already know about humans, such as:

• In my first 2001 edition (and again in my 2011 edition) of “Diet Simple,” I quoted the National Institutes of Health National Task Force for the Prevention and Treatment of Obesity, which reviewed some 28 medical studies on weight cycling. Their conclusions:“There is no convincing evidence that weight cycling in humans has adverse effects on body composition, energy expenditure, risk factors for cardiovascular disease, or the effectiveness of future efforts at weight loss,”
  
• The longest running study of successful weight loss maintainers, The Weight Control Registry, established in 1994 and following more than 5,000 people, has found that many successful weight loss maintainers tried several times to lose weight – and often yo-yo’d a lot, before they finally kept the weight off for good,
• Calorie-restriction research is compelling and shows our bodies go through amazingly positive changes during weight loss or calorie restriction. Calorie restriction research combined with the Ohio University study results suggest these changes may have a strong impact, even if just a portion of your life is spent losing weight or restricting calories. Some benefits of calorie restriction: 1) Reduction of blood glucose and  insulin cuts the risk of insulin resistance, diabetes and its complications, as well as heart disease, and colon cancer, 2) Reduction of oxidative damage and aging, potentially improving longevity, 3) Reduction of inflammation, a risk factor for cancer, heart disease, arthritis and other chronic diseases, 4) More youthful hormone levels and a reduction of dangerously high hormone levels and growth factors related to cancers, and, finally, 5) calorie restriction reduces body fat, which research shows has many benefits.

“We used to think body fat was inert, but it isn’t,” says Luigi Fontana, Instructor of medicine at Washington University’s Division of Geriatrics and Nutritional Science. “Fat tissue produces hormones, pro-inflammatory chemicals which regulate metabolism, the immune system, inflammation and the progression of artery hardening, so that when you have less body fat, you get many biological benefits.”

There are many advantages to calorie restriction. But there are downsides to severe calorie restriction, too.  In fact, scientists are not recommending it to humans as a way to stay healthy since the research is not complete. Lower metabolisms can cause irritability or depression in some people or may backfire and lead to an eating disorder. If you eat too few calories and hormone levels lower too much, this may lead to infertility problems or increase chances of osteoporosis in women.

Still, it’s useful to think about the discoveries and to find ways to integrate some of the important insights into your daily life.

• Reduce plasma insulin with exercise. It naturally clears glucose from your blood stream and that keeps insulin levels low. It creates a condition physiologically similar to calorie restriction. People who are more active have less disease and live longer,

• To reduce oxidative damage, eat more foods high in anti-oxidants, such as berries, dark green and deep orange vegetables, such as spinach, kale, pumpkin, carrots, cabbage, and broccoli,
• To reduce inflammation, eat more foods high in omega 3 fatty acids, such as fatty fish like salmon, herring and sardines, or vegetarian sources like walnuts and flax seeds,
• To reduce hormones, growth factors and cell proliferation, lose weight,
• To keep calories at low but healthy levels while still feeling full, increase consumption of high fiber, nutrient-dense, low calorie foods such as vegetables and fruits. Reduce consumption of nutrient-poor, calorie-dense processed and refined foods like chips and sweets.

And with regard to yo-yo dieting, while, of course, it is best to be at your ideal, healthy weight and stay there, the Ohio University study means it doesn’t hurt to keep trying, and may even be beneficial…

As Winston Churchill so memorably said:  “NEVER, NEVER, NEVER GIVE UP!”

**See me discuss this study on ABC-7 today on the 5 pm News Program