How dieting prevents you from losing weight
Following on from last Mondays blog post, How eating more can help you lose weight! today, how dieting prevents you from losing weight huh? Im sure you’re all like what, Adam’s gone crazy, he talked about less calories and being more active makes me lose weight… uhuh, yeah this does hold true, but it’s not indefinite/infinite. Our bodies are super impressive at adapting to repetition. (1) How is this applicable to dieting? Let’s look at the research.
Metabolism
You’ve all heard this term, but what does it actually mean?
“Metabolism is the chemical processes that occur within a living organism in order to maintain life.” (Online dictionary)
There is an obscene number of chemical reactions that occur all the time within our body. What is important to us and what we will discuss today is Basal Metabolic Rate, that is, the number of calories your body requires/burns if you were to do absolutely nothing all day long. As you can imagine this varies vastly from human to human and many factors are involved;
Muscle Tissue
I’ve talked with many of you about this in the past, but here it is again, muscle requires energy in order to perform an action, whereas fat does not. Therefore it is safe to assume that more muscle = more calories burned EVEN WHEN SITTING STILL.
Age
It goes without saying that age plays an important role here. As we age our metabolism slows down, this is impart, due to loss of muscle mass (start resistance training!) and also changes to your hormone production.
Body Size
Larger people typically will have a higher BMR, they are carrying more weight regardless of whether it is muscle or fat, the muscles they do have require calories/energy in order to help them move around.
Gender
Unfortunately ladies, the research shows that men typically have a faster metabolism than women.(2)
Hormonal Factors
Imbalances in your thyroid production can slow or speed up your BMR. Thyroid status has been heavily researched with evidence concluding that thyroid hormone Status correlates with body weight and energy expenditure. Hyperthyroidism, where your body produces more thyroid hormone than it needs, promotes a hyper-metabolic state, increasing resting energy expenditure and weight loss. Conversely, hypothyroidism is when the body does not produce enough thyroid hormone, reducing resting energy expenditure and frequently results in weight gain.(3, 4, 5)
Diet
Food impacts our metabolism and what foods you eat impact your BMR.
So, how does dieting prevent you from losing weight? Well, a study at Washington University found that eating a low-calorie yet nutritionally balance diet lowers concentration of a thyroid hormone called triiodothyronine (T3). T3 is responsible for controlling the body’s energy balance and cellular metabolism.(7)
Circling back to our thyroid section, we learned that low production of thyroid reduces resting energy expenditure, but that’s not all. Once you’ve decided you’re done dieting and can’t handle it any longer and want to eat “normally” your new “normal” is not the same as it was prior to starting on your dieting journey. What does this mean? Well, simply put, you’ll gain weight, and most likely, more weight AND faster than you did previously. Not only does caloric restriction for extended periods of time effect T3, it also has a a negative impact on the production of cortisol, our stress hormone, which further hinders weight loss.
How do we fix this?
Perhaps you have heard the term “reverse dieting” or “diet breaks.” These are to help regulate T3 production and bring you back to normal. What do they mean? Well, reverse dieting is exactly as it sounds, however, the difference here is that we increase calories at a slow rate rather than jumping in the deep end and heading out for that burger and fries you’ve been longing for. I’ve discussed with many of you this process, gradually adding more calories to help speed up your metabolism. Hopefully this post has brought some more clarity as to why this is important. Don’t be afraid of calories, and don’t be afraid of carbohydrates.
A footnote for you all - a clinical trial looking in to the effect of low-carbohydrate diets high in either fat or protein on thyroid function discovered that the group following a high-fat diet (low carbohydrate) had a significant decline in T3 production.(8)
To summarize - listen to your trainer. (No, not just that, but do that as well!) It is important to dig yourself out of the metabolic hole you create in order to either continue on your weight-loss journey OR go back to living a “normal” life consuming foods (within reason) that you want to consume.
A second footnote for you all - if you’re interested in living longer, there’s a growing number of research papers discovering that caloric restriction and how it impacts metabolism (slowing it down) actually slows down the aging process.
If you have any questions please reach out to me!
References
“The effect of stimulus repetition on neural responses and representations,” Cognitive Neuroanatomy Lab. [Online]. Available: https://cnl.berkeley.edu/research/the-effect-of-stimulus-repetition-on-neural-responses-and-representations/. [Accessed: 13-Mar-2021]
Buchholz AC, Rafii M, Pencharz PB. Is resting metabolic rate different between men and women? Br J Nutr. 2001 Dec;86(6):641-6. doi: 10.1079/bjn2001471. PMID: 11749674.
Relations of thyroid function to body weight: cross-sectional and longitudinal observations in a community-based sample. Fox CS, Pencina MJ, D'Agostino RB, Murabito JM, Seely EW, Pearce EN, Vasan RS Arch Intern Med. 2008 Mar 24; 168(6):587-92.
Thyroid hormones and the metabolic syndrome. Iwen KA, Schröder E, Brabant G Eur Thyroid J. 2013 Jun; 2(2):83-92.
Small differences in thyroid function may be important for body mass index and the occurrence of obesity in the population. Knudsen N, Laurberg P, Rasmussen LB, Bülow I, Perrild H, Ovesen L, Jørgensen T J Clin Endocrinol Metab. 2005 Jul; 90(7):4019-24.
Brent GA. Hypothyroidism and thyroiditis. In: Williams Textbook of Endocrinology, edited by Melmed SP, Larsen PR, Kronenberg HM. Philadelphia, PA: Elsevier, 2012
Washington University School of Medicine. "Calorie Restriction Appears Better Than Exercise At Slowing Primary Aging." ScienceDaily. ScienceDaily, 31 May 2006. <www.sciencedaily.com/releases/2006/05/060531164818.htm>
Ullrich IH, Peters PJ, Albrink MJ. Effect of low-carbohydrate diets high in either fat or protein on thyroid function, plasma insulin, glucose, and triglycerides in healthy young adults. J Am Coll Nutr. 1985;4(4):451-9. doi: 10.1080/07315724.1985.10720087. PMID: 3900181.