by Tina McManus, ND
It is common at this time of year for people to make positive resolutions for change, including things like weight loss. We all know that the standard advice is to “eat less and exercise more,” but considering that the incidence of obesity or overweight is increasing, perhaps this advice is too simplistic. In fact, there are numerous factors impacting a person’s weight including diet, sedentary lifestyle, poor sleep, stress, circadian rhythm, disturbance, medications, environmental toxicants, socioeconomic status, compromised microbiome, various health conditions as well as genetic factors1. That list is not even complete, but it shows that the process of losing or gaining weight is complex. However, since it is generally accepted that the underlying physiology of weight gain is calorie intake being greater than calorie expenditure, it is worth considering if various nuances can make the “eat less and exercise more” strategy more effective.
Eat Less
Let’s face it. No one likes deprivation. The idea of going on a diet and restricting foods and calories appeals to no one. And then when you think about the advice to eat regular small meals, this calorie-restriction thing becomes even more difficult. But let’s think about the wisdom of this recommendation. Should we really be eating every couple of hours? Did we evolve to have lots of small meals? Our ancestors did not have access to grocery stores. They had to find, hunt, or grow their own food, which means that access to foods most likely varied widely, especially across the seasons. Sometimes there was feast, and sometimes there was famine. We probably evolved to respond to fluctuating calories and mealtimes.
Undulate Your Calories
The guys at Mind Pump, a group of fitness experts in CA, talk about a strategy that they recommend to their clients with great success, and this strategy is starting to be backed up by research. They call this strategy “undulating” calories for weight loss. In order to have weight loss, there needs to be a calorie deficit, i.e. fewer calories consumed than expended. This can be done through calorie restriction, but instead of aiming for the same reduced number of calories per day, they recommend varying this amount where some days there will be a small deficit, and other days there will be a larger one. This way the body is less likely to adapt to the calorie restriction by lowering the overall metabolism. In addition, this method results in fat loss while preserving muscle mass. They do a great job at explaining the concept of undulating calories for fat loss in the video below:
Intermittent fasting is a concept that is gaining popularity, and it can be an effective way to undulate calories. Intermittent fasting is a form of calorie restriction that can be done in a variety of ways by fasting for periods lasting anywhere from 14-48+ hours. This means that a person might fast one or two days per week, or they might limit when they eat to an 8-10 hour window during the day. Studies have shown that intermittent fasting can lower insulin resistance, protect against neurodegeneration, and reduce systemic inflammatory diseases, as well as promote weight loss2. “Intermittent energy restriction” (IER) has been proposed as an umbrella term to include intermittent fasting (whole days of fasting) and time-restricted feeding (limited windows during which feeding happens)3. The reason for distinguishing the difference is because in intermittent fasting, there is a caloric restriction, meaning that the missed calories on fasted days are not made up for on the fed days. In time-restricted feeding, however, calorie restriction is not guaranteed, but often fewer calories will be consumed when the feeding window is shortened. Time-restricted feeding positively reinforces the body’s circadian rhythm and may also have a positive metabolic effect by shifting the gut microbiome to one less likely to promote weight gain4. Rather than counting calories, shifting time periods during which one eats and varying this throughout the week might be the most sustainable way to undulate and reduce calories while avoiding or minimizing the body’s compensatory mechanism of lowering metabolism.
Human Energy Metabolism
Human energy expenditure is made up of three things: the basal metabolic rate, the thermic effect of food, and activity thermogenesis. The first two account for about 70% of energy expenditure, and they tend to be rather stable and dependent on body size5. Activity thermogenesis is the most variable of the three, and it includes exercise-activity thermogenesis (EAT) and non-exercise activity thermogenesis (NEAT).
Exercise is defined as activity that is intentionally engaged in for health and physical fitness. While all forms of exercise are good for health, happiness, and longevity, EAT actually contributes very little to the daily energy expenditure for most people. For example, if a person exercises less than 2 hours per week, their EAT will only increase expended calories by approximately 100/day5 or 700 kcal/week; however, to achieve weight loss, this amount should be closer to 2000 kcal/week.6 This is not to say that exercise is not worthwhile. It is in fact one of the most important things you can do for your general health and wellness; however, in terms of increasing your energy expenditure, it has a smaller impact for most people than the potential of NEAT.
NEAT accounts for all other physical activity that a person engages in throughout the day, and it can vary between individuals by as much as 2000 kcal/day!5 Our modern lifestyle with its emphasis on convenience has created a society of sitters instead of walkers. Working at a desk, driving cars, going through drive-throughs, watching television, using technology – all these things encourage sitting. Research has shown that overweight subjects sit on average 2.5 hours more per day than lean subjects.5 Doing things like parking further away, taking the stairs instead of the escalator, getting up from your desk more frequently can have a significant impact on energy expenditure throughout the day. Even chewing gum and fidgeting have an impact (see the graphic below). These little activities add up, and so focusing on NEAT to increase metabolism might be the most achievable and sustainable way to address the “exercise more” part of the conventional advice.
The best way to start moving more is to get an idea about how much you are currently moving. There are lots of ways to track your activity. A while back, I decided to get an Oura ring to track my sleep and heart rate variability, and what I didn’t realize was that it also tracks activity. When I first started to use the ring, I was studying for my board exams. It was eye-opening to see how big of a toll sitting and studying would take on my activity levels if I didn’t make an effort to get up and move. It has also been interesting to see the variation in how many calories I burn day to day, depending on my NEAT activity. For example, it is easy to meet activity goals on days when I am doing chores or running errands, but on days when I am working at the computer, it can be hard to burn as little as 100 kcal.
For most people, type of occupation will have a big effect on spontaneous NEAT activity. For example, desk work generally results in a lot of sitting. In these cases, environmental changes like acquiring a standing or treadmill desk can make a big impact, but this is not always possible. Therefore, intentional efforts to increase NEAT will be necessary. Levine discusses an approach to increase NEAT that is represented by the acronym STRIPE:8
S = select a NEAT-activity that is enjoyed and start it,
T = targeted, specific individual goals must be defined,
R = rewards need to be identified for reaching the defined goals,
I = identify barriers and remove them,
P = plan NEAT-activity sessions,
E = evaluate adherence and efficacy.
Walking is an excellent way to increase your NEAT. Going for a quick walk at lunch time or during a short break is a great way to get your blood flowing and increase your NEAT. For me, I love to dance. During the months that I was studying, I would take 5-10 minute dance breaks. Those breaks were fun and energizing, and they helped me to meet my NEAT goals. I have continued my dance breaks when I can. Because NEAT includes all non-exercise activity, the sky is the limit. Brainstorm on where you can find opportunities to increase movement, especially when you are already moving. Are there opportunities where you can walk instead of drive? What about carrying a basket at the supermarket instead of pushing a cart? Can you set a timer to get up from your desk at least once an hour?
Weight loss is a complicated topic, and the best chances to have success is to use a multifactorial approach. In this article, I barely scratched the surface of ways to incorporate ways to “eat less and exercise more”, but hopefully the ideas of undulating calories, intermittent fasting, and increasing NEAT sound more “do-able” and sustainable than the traditional ideas of eating restrictive, unappealing meals and engaging in strenuous exercise. There are many other things to consider, including health conditions that can contribute to weight gain and make fat loss difficult. Examples include hypothyroidism, metabolic syndrome PCOS, chronic pain or fatigue. If you suspect underlying health issues are contributing to your struggle with weight, feel free to schedule an appointment with Dr. Richter or myself for a thorough workup. In any case, here is to a happy and NEAT New Year!
REFERENCES:
1. Hubácek JA. Eat less and exercise more – Is it really enough to knock down the obesity pandemia? Physiol Res. 2009;58(SUPPL.1).
2. Cho Y, Hong N, Kim K, et al. The Effectiveness of Intermittent Fasting to Reduce Body Mass Index and Glucose Metabolism: A Systematic Review and Meta-Analysis. J Clin Med. 2019;8(10):1645. doi:10.3390/jcm8101645
3. Rynders CA, Thomas EA, Zaman A, Pan Z, Catenacci VA, Melanson EL. Effectiveness of intermittent fasting and time-restricted feeding compared to continuous energy restriction for weight loss. Nutrients. 2019;11(10):1-23. doi:10.3390/nu11102442
4. Chaix A, Zarrinpar A. The effects of time-restricted feeding on lipid metabolism and adiposity. Adipocyte. 2015;4(4):319-324. doi:10.1080/21623945.2015.1025184
5. Levine JA, Vander Weg MW, Hill JO, Klesges RC. Non-exercise activity thermogenesis: The crouching tiger hidden dragon of societal weight gain. Arterioscler Thromb Vasc Biol. 2006;26(4):729-736. doi:10.1161/01.ATV.0000205848.83210.73
6. Schoeller DA, Shay K, Kushner RF. How much physical activity is needed to minimize weight gain in previously obese women? Am J Clin Nutr. 1997;66(3):551-556. doi:10.1093/ajcn/66.3.551
7. Levine JA, Vander Weg MW, Hill JO, Klesges RC. Non-exercise activity thermogenesis: The crouching tiger hidden dragon of societal weight gain. Arterioscler Thromb Vasc Biol. 2006;26(4):729-736. doi:10.1161/01.ATV.0000205848.83210.73
8. Levine JA. Nonexercise activity thermogenesis – Liberating the life-force. J Intern Med. 2007;262(3):273-287. doi:10.1111/j.1365-2796.2007.01842.x