Non-Exercise Activity Thermogenesis - The Unsung Hero of Weight Management

Conventional approaches to weight management, and why they fall short

Our society is always looking for the weight management silver bullet; that magic diet, pill, or fitness machine that will shed excess fat and lead to a fit and firm body. Over the years, a multitude of services and products have hit this multi-billion dollar industry, yet we continue to see obesity rates rise, along with its associated co-morbidities. When it comes to weight management, focusing on the fundamental constituents of healthy living, rather than fads and gimmicks, is always the best bet. However, these common approaches do not always lead to the attainment of desired results.

Most primary healthcare practitioners value lifestyle medicine and its incorporation into patient care, and this is especially true for Naturopathic Doctors. Within the realm of lifestyle medicine, physical activity is usually at the top of the list when considering a weight management plan. However, it can be difficult to settle on the “best” exercise or workout to help support healthy body composition, as it often depends on various factors. When developing or referring out for the development of an appropriate physical activity regimen, practitioners must consider factors such as the patient’s medical history, injuries, health risk factors, goals, current fitness level, level of commitment, and realistic time allowance to the program, just to name a few. Naturopathic Doctors may also assess for structural and functional imbalances, which may predispose a patient to injury, by using orthopedic tests, functional movement screens, muscle strength tests, and neurological evaluations. This assessment allows for the development of an individualized physical activity regimen. Those individuals who do not seek assistance in developing a personalized program tend to experience sub-optimal results. Once a full assessment is complete, the workout regimen can be implemented, and generally involves physical activity at an intensity of 65-85% of the patient’s age-determined maximal heart rate, 30-60 minutes per day, 3-5 days per week, and includes a combination of cardiovascular exercise and strength training.^[1]

Secondly, Naturopathic Doctors who are working with patients to help them achieve their weight management goals will strongly emphasize the importance of a healthy and balanced diet. The predominant consideration revolves around a simple equation: calories ingested minus calories expended equals net caloric balance. In other words, calories from food consumed minus calories burned will dictate whether a positive (weight gain) or negative (weight loss) caloric balance exists over time. To put things in perspective, one pound of body weight equals about 3500 calories; therefore, if an individual has a daily caloric deficit of 500 calories (either from burning extra calories or consuming fewer calories), they stand to lose about one pound of body weight per week.^[1] This system can work well if the individual is comfortable tracking his or her dietary and physical activity habits, though it is a fairly demanding process. Also, it does not take into consideration the patients metabolic rate, food choices and possible sensitivities, underlying disruptive pathologies, the source of weight loss (muscle or fat mass), or the promotion of lasting healthy behaviour change, all of which can contribute to a limitation in maintaining results. In response, Naturopaths will educate patients around healthy food options, including a plant-based diet combined with healthy fats, lean protein, and mineral/vitamin supplements that will compensate for known deficiencies and/or support the patient in achieving their goals.

These fundamental approaches to healthy weight management, centered on exercise and nutrition, are certainly important, but they are nothing new. Despite general knowledge and awareness of their importance, many individuals continue to struggle with weight management. As a result, this article will not delve into exercise or diet in any greater detail. Rather, this article will explore another, somewhat undervalued, component of weight management that plays a significant role in the achievement and maintenance of a healthy body composition.

NEAT (non-exercise activity thermogenesis)

As mentioned earlier, in order to lose weight, one must consistently stay in a negative caloric balance. This provides the rationale for the low-calorie diets and calorie-burning exercises promoted in the fitness industry. However, when it comes to how many calories an individual is burning in a given day, exercise is a relatively small player. There are three main components to daily energy expenditure: i) basal metabolic rate – the energy needed for basic cellular functions to occur, ii) thermal effect of food – the energy it takes to break down, absorb, and store food/fuel, and iii) activity thermogenesis – which consists of exercise and non-exercise activity thermogenesis (NEAT).^[2-5] Basal metabolic rate accounts for approximately 60% of energy expenditure in a sedentary adult, with individuals having greater lean body mass (non-fat mass) having higher basal metabolic rates.^[2] The thermal effect of food contributes to approximately 10% of energy expenditure and does not vary greatly from one person to the next.^[2]

Source: Levine JA. Non-exercise activity thermogenesis (NEAT): environment and biology. Am J Physiol-Endoc M, 2004; 28:E675-E685.

With respect to activity thermogenesis, exercise and NEAT can be examined. The average “exerciser” exercises about 2 hours per week, which equates to burning less than 100 calories per day.^[2] This is not much when considering that average calorie intake can be anywhere from 1500-2500 calories per day,^[1] and someone trying to lose weight needs to have a negative caloric balance. Further, individuals who spend no time exercising will have an exercise thermogenesis of zero. Dr James A Levine, MD, PhD, has extensively researched NEAT and describes it as follows:^[4] “Non-exercise activity thermogenesis is the energy expenditure of all physical activities other than volitional sporting-like exercise. NEAT includes all those activities that render us vibrant, unique and independent beings such as dancing, going to work or school, shoveling snow, playing the guitar, swimming or walking in the modern mall. NEAT is expended every day and can most easily be classified as NEAT associated with occupation and NEAT associated with leisure.” NEAT is contrasted to exercise in that exercise is a volitional act, engaged for the purpose of developing or maintaining physical fitness. Research has shown that occupation is the greatest determinant of NEAT, to the point where a labour-intensive job can lead to an increased expenditure of 1500 calories per day.^[2] To put things in perspective, here are some common examples of various activities and their impact on NEAT:^[2]

Source: Levine JA. Non-exercise activity thermogenesis (NEAT): environment and biology. Am J Physiol-Endoc M, 2004; 28:E675-E685.

Integration of NEAT into weight management and additional considerations

When examining the controllable and modifiable components of energy expenditure, namely exercise and NEAT, and considering the relatively small impact of exercise, it is of great importance that NEAT is optimized. In a study conducted by Dr Levine and his team, it was concluded that participants who were overfed but increased their NEAT to the greatest degree ended up gaining the least fat, whereas those who were overfed but did not increase their NEAT gained the most fat.^[4] In other words, NEAT plays a pivotal role in healthy weight management and is something everyone has control over. This may involve choosing a vocation or hobby that is more labour-intensive in nature or simply being more cognizant of how sedentary one is on a day-to-day basis and gradually introducing more movement.

In addition to optimizing NEAT, engaging in regular exercise, and consuming a healthy and balanced plant-based diet, individuals can enhance their results with several adjunctive considerations. Seeking regular Naturopathic medical care helps expedite the process by allowing for a thorough health assessment and individualized program development, accountability, support, motivation, and in-office treatment to address any underlying barriers to attainment of goals. This can include previous injuries and/or muscle imbalances, hormonal imbalances, immune dysfunction, sleep issues, digestive complaints, neurological/movement disorders, and mood disorders. Moreover, seeking the supervision of a Registered Kinesiologist or qualified Fitness Trainer can help ensure that movement patterns engaged in during exercise are correct and mitigate risk of future injury. Further, tracking applications and devices may be used to monitor caloric balance and track eating patterns and exercise habits.

Lastly, an underappreciated part of weight management is body image and self-acceptance. Due to various past experiences and relationships, destructive and reinforced thought patterns can lead to a multitude of barriers to health. The practice of mindfulness can be helpful, where mindfulness refers to the act of intentionally paying attention to the present moment without judgment.^[6] By connecting to the present moment, mindfulness allows for real-time realizations of how time and energy are being spent (i.e. the recognition that one has being sitting for an extended period of time and should get up and move). Mindfulness also helps provide the platform for even deeper healing and change through the application of equanimity, or non-judgment. Through this lens, no effort is “not good enough”. All attempts to better one’s health are purposeful and well received, while mitigating the damage that can be caused by negative self-talk. In addition to the basic practice of mindfulness, Cognitive Behaviour Therapy (CBT) can contribute to lasting lifestyle changes that support healthy weight management by further facilitating awareness-development and behaviour change. The intricacies of mindfulness theory and practice, as well as CBT, extend well beyond the scope of this article, but can be explored in Full Consciousness Living by John Kabat-Zinn and Mind Over Mood by Dennis Greenberger and Christine A. Padesky, as well as through consultation with a Naturopathic Doctor.

Conclusion

Exercise and healthy eating are fundamental components of achieving and maintaining healthy body composition. However, health and wellness certainly extend beyond sweating it out at the gym a couple of times per week and squeezing some vegetables onto the plate. Incorporating more movement into daily living is a crucial factor when it comes to weight management. Interestingly, the benefits of NEAT do not stop there, as recent research demonstrated that NEAT also plays a role in the achievement of healthy insulin sensitivity, waist circumference, high-density lipoprotein cholesterol levels, and blood pressure in patients with type-2 diabetes.^[7]

In conclusion, to promote overall healthy body composition, and even reverse obesity, it is recommended that individuals stand and/or are ambulatory for 2.5 hours daily, thus increasing their NEAT.^[3] Looking to the future, it is also recommended that our society re-engineer work, school, and home environments to make active living the option of choice. With these fairly straightforward recommendations of simply moving more throughout the day, research has demonstrated that we can take control of our weight and make a positive impact on current obesity trends. This can be achieved by examining where NEAT can be incorporated or enhanced in ones daily life. An individual could make an effort to take the stairs instead of elevators, get off a few stops early on public transit, park a fair distance away from the final destination, take the dog for a walk instead of just letting it out in the backyard, and so on. This practice can be as simple or creative as one chooses, but the bottom line is always the same – just move.