Blog - Richard Geres Personal Training - Weight-Loss, Fitness, Research
Sat, 14 June 2014
How this 'trick' can make you burn an additonal 600kcal per day (it's not exercise)
Why is it that some people gain weight immediately following overeating, while others seem to be able to eat what they want and yet remain slim?
While hormones like thyroxine, estrogen and cortisone as well as medications like the contraceptive pill, anti-inflammatory drugs and anti-depressants may have an influence on the amount of fat we store, a lot has to do with Non-Exercise Activity Thermogenesis (NEAT), or to put it simply, the amount of energy expended in activities that are not exercise-related.
The amount of energy used by our body depends on 3 principal components: basal metabolic rate (BMR), thermic effect of food (TEF) and activity thermogenesis.
BMR is the energy expended when an individual is lying at complete rest. In individuals with sedentary occupations BMR accounts for approximately 60% of total daily energy expenditure. Three-quarters of the variability in BMR is predicted by lean body mass (muscle, bone, internal organs, skin). Larger amounts of muscle mass help to burn more calories even at rest. TEF is the energy expended during digestion, absorption, and storage of food and accounts for approximately 10-15% of total daily energy expenditure.
Activity thermogenesis can be separated into two components: exercise-related activity thermogenesis and non-exercise activity thermogenesis (NEAT). Exercise related thermogenesis is very small in comparison to NEAT, even in avid exercisers. NEAT is the predominant component of activity thermogenesis and is the energy expenditure associated with all the activities we undertake as vibrant, independent beings. NEAT includes the energy expenditure of work, labour, leisure, sitting, standing, walking, talking, toe-tapping, playing guitar, dancing, shopping and fidgeting.
NEAT ranges from about 15% of total daily energy expenditure in very sedentary individuals to 50% or more of total daily energy expenditure in highly active individuals and therefore may play a very significant role in controlling body weight.
The NEAT study
In a study conducted by Dr. James Levine in 1998, 16 nonobese volunteers were fed 1000 kilocalories per day in excess of weight-maintenance requirements for 8 weeks. In theory, this should have resulted in a weight-gain of approximately 8kg over the 8 week period (remember: it takes 7000kcal extra to gain 1kg of fat), but the amount of weight gained varied considerably between subjects. In fact, fat gain varied 10-fold among the volunteers, which is a huge variation, ranging from a gain of only 0.36 kg to a gain of 4.23 kg, and was inversely related to the increase in total daily energy expenditure. On average, 432 kcal/day of the excess energy ingested was stored and 531 kcal/day was dissipated through increased energy expenditure (one subject burnt an extra 692kcal per day through NEAT!!).
So what could have accounted for the huge differences in weight-gain observed in these 16 subjects?
The author justifies that NEAT was responsible for the huge variation. While some people involuntarily increase NEAT when consuming a higher calorie intake, others do not. The study showed clearly that those subjects that produced the most amount of NEAT, which was measured using specific accelerometers, showed the least increase in weight (the test subjects were intentionally advised not to increase their exercise activity during the duration of the study in order not to skew results).
Therefore, simple adjustments in daily activity can have a long-term effect on weight maintenance. Using the stairs instead of the elevator, walking across to your work colleague instead of skyping or emailing, getting up frequently from your desk and walking a few steps as well as cleaning, gardening and carrying your shopping can have a cumulative, positive effect in helping you lose weight or just keep it off.
Another important point: Do not decrease your NEAT, just because you've done some voluntary exercise. It is not uncommon to see gym members engage in an hour of physical activity, only to resort to the elevator on their way out to avoid climbing a flight of stairs!! Also, spending the remaining evening hours after exercise slumped over your sofa will not contribute to NEAT!
Are your kids restless, and can't sit still? While their fidgeting may be making you or their teacher nervous, these kids are just trying to expend energy and are highly likely to be lacking physical activity! You need to get them to a playground or to a sports club and let them let off some steam! Kids spend way too much time in front of tablets, PCs and TVs! Limit their time on these devices and get them out of the house!
Levine JA et al (1999) Role of Nonexercise Activity Thermogenesis in Resistance to Fat Gain in Humans Science 283: 214-216
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