How Skinny Fat Affects Metabolism

People consistently ask me how skinny fat affects metabolism. Is a skinny fat metabolism different than a regular metabolism? What does the current science say?

Metabolism is essentially how the body burns calories. Scientifically, metabolism (1) is defined as, “the whole sum of reactions that occur throughout the body within each cell and that provide the body with energy.” The ‘energy’ is calories. Physical and chemical metabolic reactions/processes include no less than breathing, circulating blood, controlling body temperature, contracting muscles, digesting food and nutrients, eliminating waste through urine and feces, and the functioning of the brain and nerves.

Your unique genetic body composition directly influences your specific metabolism. Muscle tissue, at rest and when active, burns calories. Science currently recognizes that one pound of muscle burns roughly 6 calories (2) at rest. The more muscle tissue you have, the stronger/faster your metabolism and the more calories you burn.

Of course, how much regular white/yellow fat tissue as well as skinny fat tissue you have also influences your metabolism. Science currently recognizes that regular fat and skinny fat (thin fat, cellulite) only roughly burn two to three calories (3) per pound at rest. Which is half to two-thirds less than muscle tissue. The more regular fat and/or skinny fat that you have, the slower/weaker your metabolism and the fewer calories you burn.

Thus, even when you are sitting and doing very little to nothing, your muscle/mass still burns significantly more calories than your regular fat (particularly in excess like with obesity) or skinny fat, if you are experiencing any.

How Skinny Fat Affects Metabolism – The Inaccurate Standard BMI, Standard BMR, and Standard BT1

Science and medicine must have accurate standards (4). The NIH officially recognized the current BMI as the American standard in 1998 (5, 6). Useful as a general guideline, the Standard BMI fails to effectively or efficiently account for genetics, excess muscle/mass (genetic or added via exercise), skinny fat, racial discrepancies, gender differences, age, and the like.

Basal metabolic rate (BMR) is the bare minimum number of calories your unique body requires to function daily. It is generally recognized and accepted in scientific and medical circles that the Mifflin St. Jeor BMR equation (7, 8) is the BMR gold standard for obese and non-obese individuals. In terms of Total Daily Energy Expenditure (TDEE), the Revised Harris-Benedict formula (9, 10) is considered the gold standard and calculates your total daily estimated calories burned relative to BMR, all activity, exercise, and body functionality.

However, because skinny fat science is so new, both the Mifflin St Jeor formula and the Harris-Benedict equation fail to properly account for skinny fat which affects their accuracy. The more skinny fat you have, the more likely your estimated daily Standard BMR and TDEE calories are over-estimated. The Scientific Metabolism Quiz Health Score uses a proprietary algorithm based on the Body Type Science research data (11) to include skinny fat, offering additional Adjusted BMR and TDEE calorie estimates.

The Standard Body Type One (BT1)

When you go to see your doctor, your body, like all human bodies, is being judged by the Standard Body Type One (BT1) found in any scientifically approved human body anatomy book/resource (12), including all 600+ developed muscles. The Standard BT1 is the only scientific body type recognized by mainstream science and medicine, and thus, every human being is a Body Type One.

If you do not look like a Standard BT1 then you are eating too many calories above Standard BMR/TDEE which has caused you to gain excess regular white/yellow fat and taken you outside of safe Standard BMI. Once you lose the excess regular fat weight and are within safe BMI again, you are once again a Standard BT1. However, the Body Type Science research data (11) shows that not everyone (13) is born in a Standard BT1 due to genetics — more specifically skinny fat genetics including normal weight obesity, thin fat, and cellulite. 

As the global obesity epidemic rages out of control (14, 15, 16) and gets worse (17, 18), mainstream science and medicine continue to hold to outdated, inaccurate standards (13). Regular fat weight loss and gain are directly influenced by unique genetic body composition and metabolism, no less. If people are, indeed, following inaccurate BMR and TDEE calorie estimates that are too high (they are eating too much) while being held to unfair body type (shape) and composition standards, is it any wonder that so many people are experiencing issues with regular fat weight loss and management no matter how hard and diligent they work to lose that excess regular fat weight relative to healthy diet, exercise, and lifestyle routines?

Improving Metabolic Rate – How Skinny Fat Affects Metabolism

If you are genetically blessed with a Standard Body Type One and/or the ALK skinny gene (19), especially the younger and healthier you are, then you have a strong/fast metabolism and can likely eat whatever you want while finding it hard to gain weight. But if you are not genetically blessed and instead are experiencing some type of skinny fat tissue like thin fat or cellulite, the more you are experiencing the slower/weaker your metabolism. You can reduce skinny fat, but unlike regular fat, you cannot get rid of it.

So, your skinny fat metabolism is always at a slight disadvantage, at least. You can change your unique metrics and improve your metabolic rate by exercising regularly and being as healthy (20, 21, 22, 23) as possible including losing excess regular fat weight, maintaining a safe Standard BMI, eating a healthy diet, and living a healthy lifestyle (sleep, stress, etc.). The Scientific Metabolism Quiz — which you can take as many times as you want — allows you to track your metabolic changes as your unique metrics change.

The Best Skinny Fat Lifestyle, According to Science

References

1. NIH, National Library of Medicine: Physiology, Metabolism, September 12, 2022, Arturo Sánchez López de Nava; Avais Raja. https://www.ncbi.nlm.nih.gov/books/NBK546690/
2. Stronger By Science: How many additional calories does each pound of muscle burn?, June 14, 2023, Greg Nuckols. https://www.strongerbyscience.com/calories-muscle-burn/
3. Livestrong: Is It a Myth That Muscle Burns More Calories Than Fat?, Stan Mack. https://www.livestrong.com/article/447243-is-it-a-myth-that-muscle-burns-more-calories-than-fat/
4. AMA Journal of Ethics: The Origins and Promise of Medical Standards Of Care, Eleanor D. Kinney, JD, MPH. https://journalofethics.ama-assn.org/article/origins-and-promise-medical-standards-care/2004-12
5. Wikipedia: Body mass index, https://en.wikipedia.org/wiki/Body_mass_index
6. American Medical Association: AMA adopts new policy clarifying role of BMI as a measure in medicine, June 14, 2023. https://www.ama-assn.org/press-center/press-releases/ama-adopts-new-policy-clarifying-role-bmi-measure-medicine
7. Journal of the Academy of Nutrition and Dietetics: Comparison of Predictive Equations for Resting Metabolic Rate in Healthy Nonobese and Obese Adults: A Systematic Review, May 2005, David Frankenfield, MS, RD, Lori Roth-Yousey, MPH, RD, Charlene Compher, PhD, RD. https://www.jandonline.org/article/S0002-8223(05)00149-5/abstract
8. NutriAdmin: Mifflin-St Jeor Equation in Nutrition, October 25, 2023, Lucy Domingo, Registered Nutritionist Dietitian. https://nutriadmin.com/blog/mifflin-st-jeor-equation-in-nutrition/
9. NIH, National Library of Medicine: Revised Harris–Benedict Equation: New Human Resting Metabolic Rate Equation, January 28, 2023, Eleni Pavlidou, Sousana K. Papadopoulou, Kyriakos Seroglou, and Constantinos Giaginis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9967803/
10. VeryWellFit: How to Calculate Your Basal Metabolic Rate (BMR), May 20, 2021, Paige Waehner, CPT (Medically reviewed by Vanessa Nzeh, MD). https://www.verywellfit.com/basal-metabolic-rate-1229751
11. Fellow One Research: Body Type Science Research Data, https://www.fellowone.com/category/fellow-one-research/the-four-body-types/body-type-science/body-type-quiz/research-data/
12. Britannica: human muscle system, July 29, 2024, Robin Huw Crompton and Bernard Wood. https://www.britannica.com/science/human-muscle-system
13. KevinMD: Why body type standards are wrong in measuring health, November 4, 2022, Marc Nelson. https://www.kevinmd.com/2022/11/why-body-type-standards-are-wrong-in-measuring-health.html
14. U.S. Centers for Disease Control and Prevention/CDC: Adult Obesity Facts, May 14, 2024. https://www.cdc.gov/obesity/php/data-research/adult-obesity-facts.html
15. U.S. Centers for Disease Control and Prevention/CDC: Childhood Obesity Facts, April 2, 2024. https://www.cdc.gov/obesity/php/data-research/childhood-obesity-facts.html
16. World Health Organization/WHO: Obesity and overweight, March 1, 2024. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
17. NIH, National Library of Medicine: By 2030, nearly half of all U.S. adults will be obese, experts predict, December 19, 2019, Melissa Healy. https://www.ncbi.nlm.nih.gov/search/research-news/7943/
18. Time: More Than Half of the World Will Be Obese By 2035, March 21, 2023, Report Says, Jeffrey Kluger. https://time.com/6264865/global-obesity-rates-increasing/
19. Science Daily: Scientists identify gene linked to thinness that may help resist weight gain, May 21 2020. https://www.sciencedaily.com/releases/2020/05/200521112617.htm
20. WebMD: Understanding Your Metabolism, March 05, 2024, Kendall K. Morgan (Medically Reviewed by Jabeen Begum, MD). https://www.webmd.com/fitness-exercise/what-is-metabolism
21. Harvard Health Publishing: The truth about metabolism, June 23, 2024, Reviewed by Howard E. LeWine, MD, Chief Medical Editor. https://www.health.harvard.edu/staying-healthy/the-truth-about-metabolism
22. Healthline: 8 Ways That May Speed Up Your Metabolism, January 11, 2024, Helen West, RD (Medically reviewed by Marie Lorraine Johnson MS, RD, CPT). https://www.healthline.com/nutrition/10-ways-to-boost-metabolism
23. Harvard Health Publishing: Does metabolism matter in weight loss?, April 16, 2024, Reviewed by Howard E. LeWine, MD, Chief Medical Editor. https://www.health.harvard.edu/does-metabolism-matter-in-weight-loss