There is a fierce competition in my home. At the end of school, my husband surprised all of us with Nike+ FuelBands — devices worn on the wrist to measure the energy you expend daily. His goal was to encourage us all to stay active during the summer. I don't think he could have fully anticipated the bloodthirsty contest that has ensued over who scores the most fuel points or has the highest number of daily steps. But it has been fun!
The kids are a bit bewildered as to why I generally run the highest numbers by midday. I explain that my day is go-go-go. Up from my desk, to the patient room, to the lab, back to rooms, back to desk, meetings and so forth. This is my NEAT, an acronym for Non-Exercise Activity Thermogenesis.
The term refers to energy consumed other than through purposeful physical activity. NEAT includes energy expended cleaning house, working in the yard, cooking in the kitchen, or walking from the parking lot to the store or work. NEAT is anything outside of dedicated exercise. Dr. J.A. Levine, a Mayo Clinic physician, wrote an excellent article on NEAT summarizing its importance in obesity and weight maintenance in The Journal of Internal Medicine (August 2007).
There are three components of our daily energy expenditure. Our baseline energy expenditure (basal metabolic rate) accounts for approximately 60 percent of daily energy used. Burning our food fuel accounts for another 10 percent of daily energy needs. The remaining 30 percent of energy is from both NEAT and dedicated exercise.
NEAT levels vary significantly. Physically active people may burn up to three times more energy than their inactive counterparts. An extremely active adult may burn up to 2,000 more calories a day. Levine's earlier research (Science, 2001) found that a physically rigorous occupation (such as construction work) might use up to 1,500 calories per day more than a sedentary office job.
Levine provides an example of an after-office evening couch potato operating a remote control who will expend about 30 calories of NEAT. Someone who arrives home and attends to housekeeping tasks, such as painting a room or pulling weeds, might expend an additional 75 to 1,125 calories.
Levine found that “obesity is associated with a NEAT defect that predisposes obese people to sit.” In studies where overweight people underwent controlled weight loss, and normal-weight individuals underwent controlled weight gain, the previously obese people continued their tendency to sit and maintain lower NEAT. The previously normal-weight (now overfed) individuals, however, maintained their high level of NEAT and “innate tendency to stand and walk.”
There are some clues as to why some people have more NEAT and fewer tendencies toward obesity.
The brain chemical orexin is one of the neurological signals for wakefulness, according to a 2001 article from Neuron. An orexin-deprived mouse demonstrated disrupted sleep patterns and obesity. Furthermore, if orexin is injected into specific parts of the brain, NEAT is increased in a dose-dependent fashion.
Obese rats have a decreased sensitivity to the effects of orexin compared to lean rats. Therefore, the obese brain is thought to be “resistant to NEAT stimuli,” according to Levine. In addition, a 2012 article from Obesity found that obese people have low levels of orexin.
According to Levine, the goal for increasing NEAT is about 2,000 calories a week, which is equivalent to walking 2½ hours daily. So, if you are overweight, have a low-energy expenditure job and have low orexin, how do you get your NEAT on?
The first way is to change your lifestyle at home. Although you could put thumbtacks on the couch to avoid sitting on it, there are healthier options. Cooking in the kitchen burns more fuel than stopping at the fast-food restaurant on the way home. Plus, with little effort, you can prepare more healthful food.
To increase NEAT at work, consider a standing desk or treadmill workstation.
Finally, I would recommend you measure daily energy through some type of objective measure. The Nike+ FuelBand has improved my family's NEAT and even our exercise regimen. My family members try daily to meet their fuel point goals. If we find ourselves running short of points, we make time to expend more energy through exercise or NEAT. We have completed many projects at the house and it has never been so clean. Fitness-oriented products similar to the Nike+ FuelBand include Fitbit, Jawbone UP and Basis.
Most of my work involves walking and standing, so by the end of the day, my fuel points are high. By the time my husband and I finish cooking, cleaning and getting the kids ready for bed, I am past my Nike+ fuel goal points on NEAT-effort alone, and that is really neat.
Dr. Jane Sadler is a family medicine physician on staff at Baylor Medical Center in Texas.