Obesity is a multifaceted chronic disease that can be affected by the dysregulation of neurohormones, environments, and genetics. The influence on genetic expression contributing to obesity begins very early in life. Epigenetics is the study of changes in genetic expression rather than changes to the genetic code or mutations. Research suggests that this influence on weight starts early and can even be influenced by parental behaviors in the pre-conception phase and in a developing infant in utero.
Many correlations have been discovered between childhood obesity and the maternal and early infancy environment. Maternal obesity has consequences for the intrauterine environment. Studies have shown that increased maternal inflammatory markers, glucose, and lipids affect perinatal neurodevelopment and metabolism. Overly simplified, the health of the mother prior to conception influences the next generation. Given this information, there has been a lot of drive toward improving health prior to pregnancy. Even modest weight loss and improvement in healthy habits pay dividends.
Significant correlations that increase childhood obesity rates include:
- Maternal insulin resistance and increased preconception BMI
- Both extremes of gestational weight
- Tobacco use during pregnancy
- Premature infants
- Bottle-fed (compared to breast-fed) due to lack of self-regulation
- Parents: 1 with obesity (3x risk), both with obesity (10x risk)
In addition, newborns delivered via cesarean section are linked with an increased childhood obesity rate. The underlying etiology of this is being studied, with a particular focus on the neonatal intestinal microbiome, including the association of C-sections, with infants having higher maternal skin microbes in the gut versus vaginal delivery. However, it is important to remember these are risk factors. Similar to how tobacco can increase the risk of cancer, there are many who use tobacco products and do not develop malignancy. Ideally, this information should be used to encourage and motivate mothers to seek preconception healthy habits and should not be utilized to induce guilt or use as a fear tactic.
Although weight loss is helpful prior to pregnancy and can help with increased fertility, there must be caution when using anti-obesity medications in those wanting to conceive, particularly topiramate, which increases the risk of cleft lips and palates. Subcutaneous weekly semaglutide is recommended to be discontinued two months before conception (per package insert), and all anti-obesity medications are contraindicated in pregnancy. Similarly, it is recommended that women do not become pregnant within 12-18 months after metabolic and bariatric surgery to prevent complications such as nutritional deficiencies, causing small-for-gestational age, and increased risks of miscarriages.
In addition to the above, adverse childhood events (ACEs) have been associated with an increased risk of obesity in children, adolescents, and even adults. Abuse, violence, incarceration or death of parents, divorce, etc., are all considered ACEs and cumulatively increase the risk of obesity later in life by affecting the hypothalamic–pituitary–adrenal axis. Mitigating these factors or providing appropriate therapy can reduce the risks of adverse health outcomes.
Sample Question
A researcher is trying to create a calculator that will take into account epigenetic factors contributing to childhood obesity rates to predict which children are most prone to obesity. He plans to have a smartphone application that contains a checklist of risk factors for childhood obesity, thus providing a percentage risk of obesity based on current risk factors. Providers would then be able to discuss with the parents how reducing certain risk factors could improve the odds of a healthy weight in their children. Which of the following should be taken into account for his predictive calculator?
A. Kids have similar obesity rates whether one/both parents have obesity
B. C-section-delivered babies are more likely to be affected by obesity
C. Maternal smoking leads to decreased childhood obesity rates
D. Breastfed infants have fewer infections but increased obesity rates
E. Insufficient gestational weight gain is protective against obesity
Next Week: Dietary plans (Mediterranean/DASH, etc.)
Upcoming: Monthly Knowledge Check. This is a review checklist of must-know items for ABOM exams based on the previous four blog topics (Wegovy® (semaglutide), Obesity Paradox/Myths, Epigenetics, and Dietary plans (Mediterranean/DASH, etc.)). In addition, this will include a brief explanation of the correct answers to previous sample questions.
For more practice questions, check out the following:
- Obesity Medicine Board Review Questions (2026): Qs 5 and 34.
- Obesity Medicine Practice Tests (2026): Q 168.
(Copyright 2026) Obesity Medicine Board Review Questions, LLC: obesitymedicinereview.com
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