I’m not big on talking about weight loss. I enjoy working with people around their weight and weight management, but I prefer to focus on health and wellness. The weight is secondary. But, I recognize that weight loss is a multi-billion dollar industry affecting millions of people each year, and it’s of concern to many, many people. So I’ve decided to start offering a cutting-edge lab test (with an easy cheek swab) to help with that goal in mind: genetic testing for weight loss by Genetic Direction. It tells you how your body responds to macronutrients (carbs, fat and protein) and certain micronutrients that affect metabolism, as well as how it responds to cardio and strength training, then takes the results and tailor makes a program for you, specifically, based on your DNA. How cool is that?

It turns out, it’s partially about what you eat and how many calories you burn…but there’s more to it than that. An individual’s ability to lose weight is affected by his or her unique genetic profile. Most people are aware that our genes determine things like our eye and hair color, or whether or not we have, say, dimples (on either one of our set of cheeks!). But our genes also reveal many things about our health, including how our bodies process foods and fuel our movements. There are seven components of weight loss that are specifically incluenced by DNA. Here is what the test can tell you:

  1. If your body is resistant to losing weight.  Several large studies have shown that people who participated in intensive and long-term diet and exercise programs exhibited significantly different weight loss responses based on their genetic profile. Those people who carried the most “unfavorable” pairs of genes lost weight with the program, but they tended to do so less than the participants who either had fewer or none of those undesirable genotypes. The “unfavorable” carriers were more likely to regain some of the weight they had lost as well.
  2. How well your body is able to process carbohydrates in your diet. The gene involved in determining this, IRS1 (seriously, IRS? Not only does it bother us about our taxes but now our carb-processing ability?), is associated with a person’s insulin sensitivity. As you may know, insulin is a hormone that acts like a key to “open” the cells to let sugar, or glucose, inside for energy. All cells use glucose for fuel, and brain and red blood cells use it as their primary source of energy. If cells have trouble digesting it, the body releases more insulin to help, which can eventually lead to insulin resistance. People who are overweight and/or physically inactive are at higher risk of insulin resistance, which can lead to diabetes or uncontrolled high blood sugar. Greater amounts of insulin can also encourage fat storage, leading to a vicious cycle of trying to figure out which came first: the chicken or the egg. One long-term study found that people with a variant of this gene who ate a high-carbohydrate, low-fat diet that consisted of high fiber, whole-plant foods had greater insulin sensitivity and lower levels of insulin resistance—and experienced greater weight loss compared to a lower-carb, higher fat diet.
  3. How much body fat you can lose through cardio exercise. Two genes have been associated with a person’s ability to lose fat from a regular cardio exercise routine. A study investigating these genes put sedentary men and women on a 20-week endurance exercise program. They exercised on a bike three times a week, starting at a moderate intensity for 30 minutes per session over the first few weeks. They built up to a longer, slightly harder workout that lasted 50 minutes for the last six weeks. Men in the study did not appear to have a different response based on their genotype. But women who carried the most “unfavorable” genotypes lost fat from the program, but they tended to lose less fat compared to those with a more favorable genotype.
  4. How well your body is able to effectively absorb folate. The MTHFR (yep, it does sound like that, and sometimes it makes you want to say it!) gene has significant associations with an individual’s folate (vitamin B9) status. Folate plays many important roles in the body, including acting as a coenzyme in DNA creation and in energy metabolism reactions. It is also involved in biochemical processes that affect the metabolism of homocysteine, an amino acid that acts as a risk factor for heart disease. Low levels of folate can lead to anemia as well.
  5. How sensitive your body is to the amount of fat in your diet. Several genes have been shown to be connected to how sensitive people are when eating a diet rich in fat. Studies show that the amount of fat in the diet affected how much weight people lost from a lifestyle intervention depending on the genotype related to these genes. One study found that those people with an “unfavorable” genotype were more likely to have a higher percentage of body fat, a larger waist size and a higher BMI the more fat they ate, compared to those without the same genotypes. Another study showed that those with a more protective genotype were able to consume greater amounts of fat without increasing their BMIs. Still another study found that people who went on a low-calorie diet that was higher in fat lost less weight if they had an “unfavorable” genotype.
  6. How your body responds to strength training. Many genetic markers have associations with people’s abilities to improve their body composition and decrease their body fat percentage from resistance exercise. Weight training improve strength and the amount of muscle a person has. Weight training can also reduce the percentage and sometimes the amount of body fat. An improved body composition, which is a higher proportion of muscle to body fat, contributes to a leaner look and potentially, a greater amount of calories burned throughout the day. People with more “favorable” genotypes in a large study experienced an improved ability to lose weight and reduce their body fat percentage with resistance training. Those with the “unfavorable” genotypes showed a decreased ability to lose weight and reduce body fat percentage from weight training.
  7. How sensitive your body is to the amount of protein in your diet. One gene has consistently been associated with body fat mass and BMI. One study found that people with the “unfavorable” genotype who dieted lost more weight, body fat and fat in the torso if they ate a moderate-to-high protein diet (25% of total daily calories) compared to a lower protein diet (15% of total daily calories), regardless of fat and carbohydrate distribution. However, they also lost more non-fat mass—which includes muscle—with the weight loss.

Genetic science is really the way of the future. It does suggest that diet and exercise programs can be enhanced or optimized when they are based on a proper understanding of a person’s specific genotype. The only way to know what yours is is by genetic testing. The GxSlim program prints out a comprehensive report based in these seven areas. Working with me, you’ll have a detailed set of recommendations to capitalize on your genetic profile. Ready to get started? Book an appointment on my “contact me” page.

Adapted from Genetic Direction


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Diabetes. 2012 Nov;61(11):3005-11. doi: 10.2337/db11-1799. Epub 2012 Aug 13. FTO genotype and 2-year change in body composition and fat distribution in response to weight-loss diets http://www.ncbi.nlm.nih.gov/pubmed/?term=22891219 Zhang X1, Qi Q, Zhang C, Smith SR, Hu FB, Sacks FM, Bray GA, Qi L.

Circulation. 2011 Aug 2;124(5):563-71. doi: 10.1161/CIRCULATIONAHA.111.025767. Epub 2011 Jul 11. Insulin receptor substrate 1 gene variation modifies insulin resistance response to weight-loss diets in a 2-year randomized trial http://www.ncbi.nlm.nih.gov/pubmed/?term=21747052 Qi Q1, Bray GA, Smith SR, Hu FB, Sacks FM, Qi L.

J Appl Physiol (1985). 2001 Sep;91(3):1334-40. Evidence of LPL gene-exercise interaction for body fat and LPL activity: the HERITAGE Family Study. http://www.ncbi.nlm.nih.gov/pubmed/11509533 Garenc C1, Pérusse L, Bergeron J, Gagnon J, Chagnon YC, Borecki IB, Leon AS, Skinner JS, Wilmore JH, Rao DC, Bouchard C. Obes Res. 2003 May;11(5):612-8. Effects of beta2-adrenergic receptor gene variants on adiposity: the HERITAGE Family Study. http://www.ncbi.nlm.nih.gov/pubmed/12740450 Garenc C1, Pérusse L, Chagnon YC, Rankinen T, Gagnon J, Borecki IB, Leon AS, Skinner JS, Wilmore JH, Rao DC, Bouchard C; HERITAGE Family Study

Proc Nutr Soc. 2014 Feb;73(1):47-56. doi: 10.1017/S0029665113003613. Epub 2013 Oct 17. MTHFR 677TT genotype and disease risk: is there a modulating role for B-vitamins? http://www.ncbi.nlm.nih.gov/pubmed/?term=24131523 Reilly R1, McNulty H1, Pentieva K1, Strain JJ1, Ward M1.

Hum Mol Genet. 2003 Nov 15;12(22):2923-9. Epub 2003 Sep 23. Interaction between a peroxisome proliferator-activated receptor gamma gene polymorphism and dietary fat intake in relation to body mass. http://www.ncbi.nlm.nih.gov/pubmed/?term=14506127 Memisoglu A1, Hu FB, Hankinson SE, Manson JE, De Vivo I, Willett WC, Hunter DJ.

Am J Clin Nutr. 2012 Nov;96(5):1129-36. doi: 10.3945/ajcn.112.038125. Epub 2012 Oct 3. TCF7L2 genetic variants modulate the effect of dietary fat intake on changes in body composition during a weight-loss intervention. http://www.ncbi.nlm.nih.gov/pubmed/?term=23034957 Mattei J1, Qi Q, Hu FB, Sacks FM, Qi L.

J Mol Med (Berl). 2007 Feb;85(2):119-28. Epub 2007 Jan 9. APOA5 gene variation modulates the effects of dietary fat intake on body mass index and obesity risk in the Framingham Heart Study. http://www.ncbi.nlm.nih.gov/pubmed/?term=17211608 Corella D1, Lai CQ, Demissie S, Cupples LA, Manning AK, Tucker KL, Ordovas JM.

J Nutr. 2011 Mar;141(3):380-5. doi: 10.3945/jn.110.130344. Epub 2011 Jan 5. APOA5 gene variation interacts with dietary fat intake to modulate obesity and circulating triglycerides in a Mediterranean population. http://www.ncbi.nlm.nih.gov/pubmed/?term=21209257 Sánchez-Moreno C1, Ordovás JM, Smith CE, Baraza JC, Lee YC, Garaulet M.

International Journal of Obesity (2015) 39, 1371–1375; doi:10.1038/ijo.2015.78; published online 26 May 2015 High genetic risk individuals benefit less from resistance exercise intervention http://www.nature.com/ijo/journal/v39/n9/abs/ijo201578a.html Y C Klimentidis1, J W Bea2,3, T Lohman4, P-S Hsieh1, S Going3 and Z Chen1

Int J Obes (Lond). 2013 Dec;37(12):1545-52. doi: 10.1038/ijo.2013.54. Epub 2013 Apr 3. FTO predicts weight regain in the Look AHEAD clinical trial http://www.ncbi.nlm.nih.gov/pubmed/?term=23628854 McCaffery JM1, Papandonatos GD, Huggins GS, Peter I, Kahn SE, Knowler WC, Hudnall GE, Lipkin EW, Kitabchi AE, Wagenknecht LE, Wing RR; Genetic Subgroup of Look AHEAD; Look AHEAD Research Group.

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