Stop Obesity from Starting In the Womb

Dr. Sears' Blog: Obesity Starts In the Womb

A new study from Harvard Medical School strongly suggests that childhood obesity begins in the mother’s womb (1). Specifically, the lower the EPA and DHA concentrations in either the mother’s diet or her umbilical cord attached to the fetus, the more likely the child will develop obesity by age 3.

It is well known from animal experiments that omega-6 fatty acids make the offspring fat, and omega-3 fatty acids make the offspring thin (2-4). This new study now confirms the same thing is happening in humans (1).

It has been demonstrated in animal models that it only takes three to four generations of a high omega-6 fatty acid intake to increase obesity in the offspring (5,6). I believe one of the driving forces for the increase in childhood obesity has been the dramatic increase in omega-6 fatty acids over the past 100 years (7). However, much of that omega-6 fatty acid increase has come from the massive increase in soybean oil consumption that started in the early 1970s. That 40-year period only represents about two generations of humans, which means it is quite likely there will be higher childhood obesity rates coming with the next generations as long as omega-6 fatty acid consumption stays elevated.

At the molecular level, the problem really starts when these excess omega-6 fatty acids are activated by ever-increasing insulin levels caused by refined carbohydrate consumption to create increased cellular inflammation. In my book “Toxic Fat“ I describe some of the political decisions and their metabolic consequences that have led to the epidemic increase of cellular inflammation that has resulted in the rapid deterioration of American health (8).

The bottom line is that this dramatic increase in omega-6 fatty acids in the diet of American mothers is causing trans-generation changes in our children due to fetal programming. This occurs in the womb and results in the final tuning of the genetic code of the fetus by changing the gene expression of the unborn child. This is called epigenetic programming and begins to explain why each succeeding generation of Americans is getting fatter and fatter (9).

Even more ominous warnings are animal studies that indicate the “reward” response (increased dopamine levels) induced by consuming junk food experienced by the mother can also be transferred to the next generation by fetal programming (10).

So what can you do about this growing genetic disaster? If you are contemplating having a child, then beginning to cut back on omega-6 fatty acids and eating more omega-3 fatty acids is a good starting point. The benefits include having a thinner and smarter child. If you already have children whose gene expression has already been altered by fetal programming, then you have to control their diet for a lifetime to prevent reverting to that altered gene expression. It’s not a pretty picture. Although you can’t escape the dietary consequences of fetal programming, you can minimize the damage by treating food as drug to manage increased cellular inflammation that is making us fatter, sicker and dumber.


  1. Donahue, SMA, Rifas-Shiman SL, Gold DR, Jouni ZE, Gillman MW, and Oken E. “Prenatal fatty acid status and child adiposity at age 3y.” Amer J Clin Nutr 93: 780-788 (2011).
  2. Gaillard D, Negrel R, Lagarde M and Ailhaud G. “Requirement and role of arachidonic acid in the differentiation of pre-adipose cells.” Biochem J 257: 389-397 (1989).
  3. Kim HK, Della-Fera M, Lin J, and Baile CA. “Docosahexaenoic acid inhibits adipocyte differentiation and induces apoptosis in 3T3-L1 pre-adipocytes.” J Nutr 136: 2965-2969 (2006).
  4. Massiera F, Saint-Marc P, Seydoux J, Murata T, Kobayashi T, Narumiya S, Guesnet P, Amri EZ, Negrel R, and Ailhaud G. “Arachidonic acid and prostacyclin signaling promote adipose tissue development: a human health concern?” J Lipid Res 44: 271-279 (2003).
  5. Blasbalg TL, Hibbeln JR, Ramsden CE, Majchrzak SF, and Rawlings RR. “Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century.” Am J Clin Nutr 93: 950-962 (2011).
  6. Hanbauer I, Rivero-Covelo I, Maloku E, Baca A, Hu Q, Hibbeln JR, and Davis JM. “The Decrease of n-3 Fatty Acid Energy Percentage in an Equicaloric Diet Fed to B6C3Fe Mice for Three Generations Elicits Obesity.” Cardiovasc Psychiatry Neurol: 2009, Article ID.867041 (2009).
  7. Massiera F, Barbry P, Guesnet P, Joly A, Luquet S, Moreilhon-Brest C, Mohsen-Kanson T, Amri EZ, and Ailhaud G. “A Western-like fat diet is sufficient to induce a gradual enhancement in fat mass over generations.” J Lipid Res 51: 2352-2361 (2010).
  8. Sears B. “Toxic Fat.” Thomas Nelson. Nashville, TN (2008).
  9. Godfrey KM, Sheppard A, Gluckman PD, Lillycrop KA, Burdge GC, McLean C, Rodford J, Slater-Jefferies J, Garratt E, Crozier SR, Emerald BS, Gale CR, Inskip HM, Cooper C, and Hanson MA. “Epigenetic gene promoter methylation at birth is associated with child’s later adiposity.” Diabetes 60: 1528-1534 (2011).
  10. Ong ZY and Muhlhausler BS. “Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring.” FASEB J 25: S1530-6860 (2011).

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About Dr. Barry Sears

Dr. Barry Sears is a leading authority on the impact of the diet on hormonal response, genetic expression, and inflammation. A former research scientist at the Boston University School of Medicine and the Massachusetts Institute of Technology, Dr. Sears has dedicated his research efforts over the past 45 years to the study of lipids. He has published 40 scientific articles and holds 14 U.S. patents in the areas of intravenous drug delivery systems and hormonal regulation for the treatment of cardiovascular disease. He has also written 14 books, including the New York Times #1 best-seller, The Zone, which have sold more than 6 million copies in the U.S. and have been translated into 22 different languages.

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