If you have heard it once, you have heard it a millions times, “dieting decreases your metabolism” or “I can’t lose weight because I have been dieting my whole life and I gain back more than I lose”. I have even heard this used as an excuse by clients when deciding whether it’s the right time to make lifestyle changes. “Why even try bothering, my metabolism is so slow from years of being on and off diets”. If these phrases are all too familiar to you then you are going to be thrilled by what you learn this month. Yo Yo dieting is technically called weight cycling by researchers, and although a specific number of pounds or dieting attempts isn’t universally accepted, its generally agreed weight cycling is the repeated loss and regain of body weight1. Two-thirds of Americans are overweight or obese and what’s probably not surprising to you is there are approximately 108 million Americans on a diet in the US at any given time3. Most dieters will make 4-5 weight loss attempts per year.3 I am going to guess at least 3 of those attempts coincide with January, bathing suit season and the holidays. The origins of the Yo Yo dieting/decreased metabolism theory may be a few small studies that reported mixed results with regards to the effects of weight cycling on physiological and psychological outcomes2. With that in mind, the researchers at the Fred Hutchinson Cancer Research Center in Seattle wanted to study whether the Yo Yo dieting theory was correct2. The Nutrition and Exercise in Woman (NEW) study authors stated it “remained unclear whether repetitive cycles of weight loss and regain have any significant effect on subsequent success in achieving weight loss, or on the metabolic changes that typically accompany it.2” The NEW study was conducted for 12 months on postmenopausal woman who were overweight or obese and had a lifetime history of weight cycling. The women were placed in either a diet and/or exercise intervention or a control group. It’s important to note, this study only looked at the physiological impact of Yo Yo dieting. Surprisingly, and fabulous news for many, the NEW study results indicated that a “history of weight cycling does not impede successful participation in lifestyle interventions or alter the benefits of diet and/or exercise on anthropometric and metabolic outcomes in women.2” Are you surprised? If you have been on and off the diet train for years and are concerned you have ruined your metabolism then you have some assurance you have not. The results of this study don’t suggest you should continue to yo yo diet, but suggest you shouldn’t let your concern over a decreased metabolism stand in your way of making lifestyle changes. Metabolism is affected by many factors including but not limited to, body composition, gender, physical activity and age.4 From age 20 on, your metabolism slows down about 2% percent every 10 years, and as we age we tend to become less active, all of which can lead to extra pounds. The scientific community may be able to establish the minimal impact of yo yo dieting on your body physically, but what happens psychologically? As dieters lose weight there is a sense of accomplishment, control and hopefulness, but as we know most diets fail, and thus those same feelings of joy can lead to feelings of deprivation, frustration, low self-esteem and mislabeling of hunger and fullness cues. The impact of these feelings can be huge barriers to you if you are in a place to finally make some permanent lifestyle changes. Breaking down these barriers, by focusing on small behavior changes which lead to slow and gradual weight loss is a good place to start. Confidence builds on small changes such as not overeating at dinner by paying attention to fullness levels, adding in a day of strength training exercise, switching from a Grande Frappacino to small size etc. With small steps, weight loss goals can be reached and become a permanent way of life, and you avoid all the drama of getting on and off a diet again. Sure lifestyle changes are slower and not as dramatic as dieting, but I promise the sense of victory at the end is even sweeter.
1. “Weight Cycling.” National Institute of Diabetes and Digestive and Kidney
Disease. National Institutes of Health, Mar. 2006. Web. 23 Sept. 2013. <http://win.niddk.nih.gov/publications/cycling.htm>.
2. Mason, Caitlin, et al. “History of weight cycling does not impede future weight
loss or metabolic improvements in postmenopausal women.” Metabolism 62
(2013): 127-36. Print.
3. ABC News. ABC News, 8 May 2012. Web. 24 Sept. 2013. <http://abcnews.go.com/
Health/100-million-dieters-20-billion-weight-loss-industry/
story?id=16297197>.
4. Mayo Clinic Staff. “Metabolism and Weight Loss: How you Burn Calories.” Mayo
Clinic. Mayo Clinic, 6 Oct. 2011. Web. 24 Sept. 2013.
<http://www.mayoclinic.com/health/metabolism/WT00006>.
Photo courtesy of zirconicusso/freedigitalphotos.net
