|Training in the fat burning zone works. But the claim that it was the best way to lose weight is certainly subject specific.|
- Training in the (fat) burning zone: In a recent study scientists from the University of Southern Queensland were not able to demonstrate the superiority of training at an intensity that equaled their thirty 45-59 year old female subjects maximal fat oxidation intensity (Tan. 2014). But this was not due to the fact that this form of training is not effective, but rather a result of the five 1h sessions of steady state cardio in "the fat burning zone" was the only form of training tested.
What the researchers did find, though, was that the exercise group obtained significant decreases in body mass, BMI, body fat % and abdominal fat mass, as well as the concentrations of triglycerides, serum leptin and blood glucose.
Figure 1: The changes in body composition with 5x / week 1h of cardio in the zone in the absence of dieting were quite impressive in this 10-week study (Tan. 2014)
In addition, there was no significant change in daily energy intake for all participants before and after the experimental period. In this particular study, the often derided cardio training "in the zone" did thus work its often doubted magic and shed 8% of the subjects body fat without dieting.
- Patterns of weight change in African Americans: Even more so than the US citizens with Caucasian ancestors, the group of African Americans is threatened by ever-increasing obesity rates. By trying to identify broad categories of people with likely different program outcomes in a large weight loss intervention study, scientists from the Center for Clinical Epidemiology and Biostatistics at the University of Pennsylvania Perelman School of Medicine tried to identify treatment approaches that would better position program enrollees for success.
Figure 2: Obesity is not an African American exclusive problem in the US, but the obesity rates - specifically for the women - are still higher in AA vs. CC citizens (Ogden. 2014).
- mean weight loss of approximately 2 kg (n = 5 519);
- mean weight loss of approximately 3 kg at 1 year, followed by 4 kg regain (n 5 61);
- mean weight loss of 20 kg at 1 year followed by 4 kg regain (n = 524).
While a weight regain of 4kg sounds huge - losing 20kg within one year and regaining only 4 means that you still lost 16kg, which is not bad and speaks in favor of the "the fatter you are, the easier you can lose tons of weight" truism. Moreover, the association with high dietary fat intakes underlines that the often cited benefits of eating more fat will occur only if the carbohydrate content of the diet is severely reduced. All in all, the study results are yet far too general to use them to deduce better weight loss prescriptions.
- Fardet & Biorie. "Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/ meta-analyses and systematic reviews." Nutrition Reviews (2014).
- Morales, Knashawn H., et al. "Patterns of weight change in black Americans: Pooled analysis from three behavioral weight loss trials." Obesity (2014).
- Ogden, Cynthia L., et al. "Prevalence of childhood and adult obesity in the United States, 2011-2012." JAMA 311.8 (2014): 806-814.
- Purcell, Katrina, et al. "The effect of rate of weight loss on long-term weight management: a randomised controlled trial." The Lancet Diabetes & Endocrinology (2014).
- Tan et al. "Positive effect of exercise training at maximal fat oxidation intensity on body composition and lipid metabolism in overweight middle-aged women." Clin Physiol Funct Imaging (2014).
- Yamada, Tomohide, Kazuo Hara, and Takashi Kadowaki. "Abstract P084: Influence Of Amount And Rapidity Of Weight Loss On The Risk Of Subsequently Regaining Weight And Drop-out From Treatment Among Patients With Severe Obesity Dieting In Hospital Without Bariatric Surgery." Circulation 129.Suppl 1 (2014): AP084-AP084.