Is The Fat You Eat The Fat You Wear?

By: Amandeep (Andy) Bains

Grandma's around the world chant a nursery rhyme to promote healthy eating:

"From the lips to the hips, the fat you eat is the fat you wear."

Those same grandmas that stuffed you with chocolate chips cookies knew right where those cookies would end up! — Or did they? It’s no surprise that when you are gaining fat, you are consuming beyond what your body needs. Yet, how our body uses the large food molecules, the proteins, carbohydrates and fats is not completely clear. Generally, carbohydrates are broken down into simpler sugars and stored as glycogen (1). Proteins are digested into amino acids and absorbed for a variety of uses from cell signaling to growing hair (1). Fats, made up of fatty acids, are absorbed easily and provide stored energy and insulation (1). Small fluctuations of the total carbohydrates, fats and proteins someone is eating tend to balance themselves over time. However, larger fluctuations and especially those eating more will result in more weight gain regardless if it is an extra serving of pasta or cake right?

Food for thought….

If our body was burning everything for energy in a perfect manner, we would be one hot furnace, but our body uses a series of chemical reactions to extract and store energy from our food. Yet, heat is still part of the equation and often a by-product of chemical reactions (1,2). For example, foods that are high in fibre and hence, carbohydrates, are going to require more energy to extract their nutrients compared to fat-rich food and in the process of conversion, also produces more heat (1,2). Further, when the body can no longer store carbohydrates as glycogen, the extra are converted into fatty acids for later use (1,2,3). Converting carbohydrates is a surprisingly inefficient process due to, in part, of their stable chemical ring structure (2). One study tested the extent of conversion by giving participants 475g of straight glucose (Sweet!) and found it to only convert to ~150g of fatty acids (3).

So, if the body is inefficient in converting carbohydrates, is the fat we eat, the fat we wear?

To answer the above, scientists took their fancy scissors, grabbed some fat, and examined it. By then comparing it to the individual’s diet, a connection was found (4,5,6). For example, monounsaturated fatty acids, (think vegetable oils), made up the largest portion of total fatty acid in adipose (fat) tissue at 54% and also diet at 42% (5). They also found similar results for trans-fats and omega-3 fatty acids (4,5,6). This correlation is shown by comparing many recent scientific studies, but also differences that came up are from people being unreliable about self-reporting (4,6). There may also be differences between men and women depending on the type of fat people eat and the source of fat (animal vs. vegetables). In particular, many of the studies centered around men over eating carbohydrate (6,7). As with anything in the world of food and nutrition, Future more research is needed, perhaps in a metabolic ward where diet can be more strictly controlled.

This naturally brings another question: Should one consume less fat to lose fat?

This may result in weight loss, and more likely when coupled with exercise, but weight loss leans on many factors. One reason it may not is that even if carbohydrates may not be stored as fat, they still will provide energy and prevent the body from needing to use fat storage (5,7,8).

So, our grandmas may have known another secret: It is easier to never gain the weight in the first place!

Grandma always knows best!

Author: Amandeep (Andy) Bains

Edited by Renée Y. Chan, MS, RD, CDN


1. Whitney EN, Rolfes SR, Hammond G, Piché LA. Understanding nutrition. 2016.

2. Reed GW, Hill JO. Measuring the thermic effect of food. The American Journal of Clinical Nutrition. 1996 Feb 1;63(2):164–9.

3. Acheson KJ, Schutz Y, Bessard T, Anantharaman K, Flatt JP, Jéquier E. Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man. The American Journal of Clinical Nutrition. 1988 Aug 1;48(2):240–7.

4. Hodson L, Skeaff CM, Fielding BA. Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake. Progress in Lipid Research. 2008 Sep;47(5):348–80.

5. Baylin A, Kabagambe EK, Siles X, Campos H. Adipose tissue biomarkers of fatty acid intake. The American Journal of Clinical Nutrition. 2002 Oct 1;76(4):750–7.

6. Acheson KJ, Flatt JP, Jéquier E. Glycogen synthesis versus lipogenesis after a 500 gram carbohydrate meal in man. Metabolism. 1982 Dec;31(12):1234–40.

7. Björntorp P, Sjöström L. Carbohydrate storage in man: Speculations and some quantitative considerations. Metabolism. 1978 Dec;27(12):1853–65.

8. Acheson KJ, Schutz Y, Bessard T, Flatt JP, Jéquier E. Carbohydrate metabolism and de novo lipogenesis in human obesity. The American Journal of Clinical Nutrition. 1987 Jan 1;45(1):78–85

9.  Parks EJ. Effect of Dietary Carbohydrate on Triglyceride Metabolism in Humans. The Journal of Nutrition. 2001 Oct 1;131(10):2772S-2774S.


About The Author:


Andy Bains

The author Andy is currently a student at UBC pursuing his second degree. He has a background in Integrated Sciences and now he is completing prerequisites to become a dietitian at UBC’s Faculty of Land and Food Systems. He wishes to address misconceptions regarding nutrition in the Indo-Canadian population and is an avid vegan and runner.

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