It is a frequent occurrence for many people losing weight to hit a weight loss plateau. They are losing fairly consistently for a few weeks or even a few months and then nothing. The number on the scale is no longer moving down. At first people will think, quite rationally, LOL, that the scale is broken or someone has messed with it. After the denial has passed, there is usually some level of panic and confusion. All of this mental and emotional turmoil is really unnecessary because the cause of the plateau, i.e., lack of weight loss, is rather straight forward and well understood. Here is the magical, super-secret reason; the person is NO longer causing a discrepancy between how many calories their body burns and how many they eat. This means that you have to eat less calories and/or burn more calories by exercising more. I wish there was more to it, but that is really the crux of the problem. Because this is a common occurrence and because there are some silly ideas of why this is happening I will dive into some of the details.
As I mentioned above, to lose weight, you must burn more calories than you eat. However, as simple and true as that is, there are a few important variables that will determine how many calories your body will burn. I will not be going into all the variables that influence the intake side. Before proceeding into the fascinating world of BMR, TEE, NEAT, EPOC, and other acronyms, which I seem to have a strong affinity for, I need to dispel a common myth about weight loss plateaus. The MYTH goes something like this;
“I don’t know what is going on, but I have not lost any weight over the past 2 weeks, even though I was losing about 2 lbs a week for a few weeks” response from a friend or “expert” (MYTH) “you are not losing weight because you are not eating enough (usually referring to the number of calories eaten), and not eaten frequently enough*, 6 times a day, so to bust through the plateau, you need to eat MORE (increase your calories) and more often”
This somewhat pervasive response is wrong, false, incorrect, not helpful, illogical and; well you get the point. The following will show why it is so.
The total amount of calories the body will burn in a day is comprised of Basal Metabolic Rate (BMR), the amount of energy to keep us alive, and physical activity (PA). There are a few factors that can modify the BMR, one of them is the amount of calories eaten. When you eat less calories, i.e., virtually EVERY diet for weight loss, than the amount that maintains your current weight the body has the ability to adjust it’s BMR and the metabolic (i.e., caloric) response to exercise , which is known as Adaptive Thermogenesis (AT). How much and how quickly this adaptation occurs depends on the amount of calorie reduction, activity levels, frequency of the deficit, and genetics (Heymsfield et al; MacLEan et al; Major, et al). All the reasons for such adaptations is very interesting, at least for some of us, but it is not really important with respect to the point of this article. The point is; when AT kicks in and you are no longer losing weight at a given calorie intake, then you HAVE to eat less calories and/or burn more with more exercise.
The other big player in the “Plateau” situation is compliance to the calorie intake that is needed to produce weight loss. It is well know that many people will not stick to a reduced calorie intake for long periods of time (Heymsfield et al). This is not usually because the person does not want to (i.e., a lack of willpower) but rather is largely due to many biological mechanisms that strongly drives people to eat more (MacLean et al). Besides the biological aspects, there are also many psychological and social aspects that also drive people to eat more (Ulijaszek et al). Collectively, these forces make eating a calorie intake that will induce weight loss difficult, particularly over the long-term.
Related to the compliance aspect is the self-reporting of energy (food) intake, i.e., what people say they ate. It is clear that many people, for many reasons, do NOT report what they actually eat (Maurer et al). The amount of calories that are underreported is often in the range of 20-50% of actual intake (Goris et al). What this means is that people are often not accurate in calculating how many calories they are actually eating. The take home point is that if you are not losing weight and think are you are eating the right amount of calories you are probably not and need to decrease your calorie intake and/or increase your exercise.
One salient quote before wrapping up.
“Question 3: What is the veracity of some of the popular beliefs related to energy balance?
A. “The typically observed weight-loss plateau at 6 to 8 mo after a weight-loss intervention is primarily due to a reduction in energy expenditure, ie, slowed metabolism.”
Although the measurement of EO [energy out] at the plateau is decreased, it does not decrease to the amount of the prescribed or self-reported energy intake. Thus, the plateau may well be attributed to failure to comply with the diet (17). Modeling studies support this interpretation and suggest that if subjects had complied with the prescribed diet, the plateau due to metabolic change would not have occurred for several years, which would have led to much greater weight loss than that observed (18). These data also emphasize that, whereas it is possible to cognitively intervene in our food intake amounts, such interventions are extremely difficult to sustain because of the biological and psychological drives to eat.” (Hall et al, p.992)
I hope it is clear that a weight loss plateau as well as the general inability to lose weight is due to a lack of a discrepancy between how many calories the body burns and how many are ingested/absorbed. There are many reasons for not achieving the discrepancy, many of which are not within our control. A common, but erroneous reason given for the plateau is that there has been to big of a calorie deficit and the common but equally erroneous remedy is to increase calorie intake. These propositions are without merit. As briefly explained above (read the referenced papers to get a much more in-depth explanation of all of the contributing factors) there are a few basic reasons why a plateau occurs. The simple, yet often NOT easy, remedy that will break a weight loss plateau is to decrease calorie intake and/or increase expenditure (exercise more).
*Meal Frequency – I did not cover this topic here because I have covered it previously HERE. The skinny on it is that eating the SAME amount of CALORIES for the day in 3 or 6 or any other frequency does NOT change the amount of calories you will burn in a day or how much weight you will lose.
P.S. While completing this article I was informed of a similar article, HERE, on the subject, which I thought was well done, so I figured I would post the link for those of you who would like to see what another weight management expert has to say on the subject.
Hall. K. et al (2012). Energy balance and its components: implications for body weight regulations. Am J Clin Nutr; 95: 989-994.
Heymsfield, S. et al (2007). Why do obese patients not lose more weight when treated with low-calorie diets? A mechanistic perspective. Am J Clin Nutr; 85: 346-354.
Goris, A. et al (2000). Undereating and underrecording of habitual food intake in obese men: selective underreporting of fat intake. Am J Clin Nutr; 71: 130-134.
MacLean, P. et al (2011). Biology’s response to dieting: the impetus for weight regain. Am J Phsyiol Integr Comp Physiol; 301: R581-R600.
Major, GC. et al (2007). Clinical significance of adaptive thermogenesis. Inter J Obesity; 31, 204-212.
Maurer, J. et al (2006). The Psychosocial and Behavioral Characteristics Related to Energy Misreporting. Nutrition Reviews; 64(2): 53-66.
Ulijaszek, S. and Lofink, H. (2006). Obesity in biocultural perspective. Ann Rev Anthropology; 35: 337-360.