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Monday, January 2, 2012

Weight loss new year resolutions


Across the globe, millions of people will commit themselves to a New Year resolution to lose weight. Almost all will fail. The 5-year cure rate for obesity is less than the 5-year cure rate for the worst cancer, a view articulated by the American Medical Association’s Council on Scientific Affairs almost 25 years ago. If dieting were a drug, it would have failed the regulatory process given that it is generally not a long-term success. Yes, there are successes but they require life long adherence to a restricted food intake.  Basically speaking, when we gain weight and retain that gain for some time, it is recognised biologically as a new norm. When we lose weight, that same norm is constantly there and constantly wishing to re-establish itself. Losing weight is easy. It’s retaining that weight loss which is huge challenge. Rule number one in weight management: Whatever your weight is now, don’t gain any more. That is a battle you can win. 
There is a second battle you can win and that is to get fit and in so doing, you will negate all of the adverse effects of overweight and obesity.  There is a wealth of literature to show that it is better to be fit and fat than slim and sedentary. Physical activity will restore blood pressure to normal and will restore the ability of the body to handle glucose thereby reducing the likelihood of obesity-related diabetes. Physical activity enhances a sense of wellbeing, something that is readily lost when people gain weight. One of the very best teaching aids on the health benefits of physical activity is available at http://www.youtube.com/watch?v=aUaInS6HIGo.

Obesity and overweight remain among the major challenges to public health nutrition that we face today. The food industry and particularly the fast food industry are the focus of attention. And whilst food intake must be a part of the solution, so too must physical activity. The problem is that we have constructed a way of life that is sedentary and we have designed a built environment to support that. One of the most inspiring exponents of physical activity is Professor James Levine from the Mayo Clinic. He has championed the concept of NEAT: Non Exercise Activity Thermogenesis.   Basically, most of the energy we consume is dissipated as basal energy needs for the functioning of our heart, lungs, kidneys, brains and son on. We also dispose of some energy in digesting and absorbing food but this is minor. After basal activity comes exercise activity thermogenesis. This area of energy expenditure is planned as a walk, a game of golf, a jog, a swim and so forth. Levine has defined another activity (NEAT), which is effectively “fidgeting” or physical activity that is not seen as intentional physical activity: picking up the phone, walking to the bathroom, standing up to give a presentation. So, lying down at complete rest costs 5.4 kilojoules (Kj) per minute. That goes up to 5.6 if seated at complete rest. Sitting but “fidgeting” raises the figure to 8.2. Now lets take a look at the same activities while standing. Standing motionless has a cost of 6.1Kj.  Standing but fidgeting now increases the value to 10.3. Walking in a stop start fashion as in many work places raises the value to 13.7. Thus simple acts of physical activity make a huge difference to energy expenditure. Levine published a scientific paper in the very prestigious journal Science in which he overfed volunteers with an additional 1000 calories per day. Before the study and during the study, ALL volitional activities were controlled and minimized. He used advanced techniques to measure body fat (DEXA scans) and energy expenditure (stable isotopes). Having overfed these people for 8 weeks with an additional 1000 calories, all subjects gained weight. However, as I’ve explained before Blog of November 14th last) , genetic variation will mean that some people will gain more weight than others. But in what fraction of energy expenditure was between-subject variation related to gain in fat mass? Not basal metabolic rate and not the thermogenesis of eating. There was a powerful negative correlation between NEAT and fat gain. The more fidgety the person, the lower the weight gain. Levine has gone on to design a unique office, which facilitates NEAT. The telephone is as far from the desk as possible. The desk can be elevated to facilitate standing and he has also designed an award-winning desk[1], which has a two-mile an hour treadmill option to facilitate NEAT (http://store.steelcase.com/products/walkstation/).
We have as much obligation to tackle our obesogenic built environment, as we have to tackle our food intake. However, architects and ergonomic designers of comfortable offices are not as attractive a villain as is the corporate food sector.





[1] Invention of the Future Award from NASA, and the Innovation Award at the World Fair

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