Non-Exercise Activity Thermogenesis

Abstract

Abstract-Non-exercise activity thermogenesis (NEAT) is the energy expenditure of all physical activities other than volitional sporting-like exercise. NEAT includes all the activities that render us vibrant, unique, and independent beings such as working, playing, and dancing. Because people of the same weight have markedly variable activity levels, it is not surprising that NEAT varies substantially between people by up to 2000 kcal per day. Evidence suggests that low NEAT may occur in obesity but in a very specific fashion. Obese individuals appear to exhibit an innate tendency to be seated for 2.5 hours per day more than sedentary lean counterparts. If obese individuals were to adopt the lean "NEAT-o-type," they could potentially expend an additional 350 kcal per day. Obesity was rare a century ago and the human genotype has not changed over that time. Thus, the obesity epidemic may reflect the emergence of a chair-enticing environment to which those with an innate tendency to sit, did so, and became obese. To reverse obesity, we need to develop individual strategies to promote standing and ambulating time by 2.5 hours per day and also re-engineer our work, school, and home environments to render active living the option of choice. Key Words: non-exercise activity thermogenesis Ⅲ physical activity Ⅲ energy expenditure Ⅲ obesity Ⅲ malnutrition T he first law of thermodynamics is the thermodynamic expression of the principle of the conservation of energy and states that when energy is added to a system, it is either stored or used to perform work. Applying this physical law to living entities, such as animals, provides us with the conclusion that when total energy intake is greater than energy expenditure, excess energy will be stored as body fat. The physiological states of overweight and obese are a consequence of cumulative excesses in caloric intake.A pandemic of obesity has spread from the US to Europe and is now emerging in middle and even low-income countries. 1 Overweight and obesity are preventable causes of death and many comorbidities including type II diabetes, hypertension, stroke, cholelithiasis, degenerative arthritis, sleep apnea, and cancer. 1 With the prevalence of overweight and obesity increasing, the urgency to understand why humans are gaining weight has intensified.Understanding the specific details of this pandemic is important. Most articles reporting the rise in prevalence of overweight and obesity use body mass index cutpoints; all have reported striking increases in prevalence. Far more profound, however, is the changes in average heights and weights across all ages. 2 For example, since the 1970s, whereas the average height of American men and women has increased, the average weight has increased 25 pounds. It is tempting to attribute the increase in average weight to changes in population demographics, ie, "middle age spread," from aging baby boomers. However, no category of individuals has escaped without weight gain, as reflected in the trend of mean weight for both men and women...

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Moderate-to-vigorous physical activity and sedentary behaviours in relation to body mass index-defined and waist circumference-defined obesity

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