Epigenetics and Body Size

For many people, weight and body size feel like a personal struggle—something to constantly manage, shrink, or “fix.” But what if your body’s tendency to store fat isn’t a failure of willpower or discipline? What if, instead, it was a brilliant survival strategy passed down through generations?

Epigenetics—the study of how environmental factors influence gene expression—helps us understand that our bodies are not just responding to the food we eat today, but also to the experiences of our ancestors. This means that past food insecurity, famine, and even chronic dieting may have shaped how our bodies regulate fat storage. Rather than blaming ourselves, we can shift the narrative to recognize that our bodies are incredibly adaptive, working to protect us in ways that are often misunderstood.

But here’s the truth: our cultural bias against fat bodies cannot be separated from social injustice and oppression. The people most likely to have experienced famine, food insecurity, and poverty—including people of color, people in poverty, and those living in food deserts—are also the people most likely to carry epigenetic markers that promote fat storage for survival. It’s not a coincidence that fat bodies are the ones most judged and discriminated against.

Weight Bias is Rooted in Racism and Classism

The idea that fat bodies are inherently bad is not based on science—it’s based on racism and classism. Historian and sociologist Dr. Sabrina Strings, author of Fearing the Black Body: The Racial Origins of Fat Phobia (2019), has extensively researched how fatphobia is deeply intertwined with white supremacy. Her work reveals that anti-fat bias originated not as a health concern, but as a way to justify racial and class hierarchies.

During the 18th and 19th centuries, European and American elites began associating thinness with whiteness, "self-discipline," and moral superiority, while depicting larger bodies—particularly those of Black women—as excessive, lazy, and undesirable. As Strings (2019) explains, early racial pseudoscience weaponized body size to reinforce colonialism, slavery, and class oppression.

This historical context matters because the same racialized fatphobia persists today. People in larger bodies—particularly Black, Indigenous, Latinx, and low-income individuals—are disproportionately blamed for their weight, labeled as “unhealthy,” and face systemic discrimination in healthcare, employment, and social settings. But these same groups are also the ones who have historically endured food scarcity, oppression, and economic hardship, leading to the very biological adaptations that promote fat storage.

In other words, fatphobia is not just about weight—it’s about controlling and marginalizing already oppressed people.

Epigenetics: How Our Bodies “Remember” Famine and Food Scarcity

Epigenetics refers to biological changes that influence how our genes function without altering the genetic code itself. These changes can be triggered by environmental stressors including famine, war, food insecurity, and chronic undernourishment (Yuan et al., 2019).

When our ancestors experienced periods of starvation, their bodies adapted by becoming more efficient at storing fat and using energy. These adaptations were passed down to future generations as a survival mechanism. If your body holds onto weight easily or resists weight loss, that’s not a personal failing—it’s an inherited response to ensure survival in the face of potential food scarcity (Painter et al., 2008).

Historical Famines and Their Lasting Impact

If your family comes from a region that experienced famine or food insecurity, it’s possible that epigenetic changes from those events still influence your metabolism today. Some of the most well-documented famines include:

• The Irish Potato Famine (1845–1852): Millions of Irish people faced starvation, and many immigrated to the U.S. Studies suggest that descendants of famine survivors have genetic adaptations that promote fat storage and energy conservation (Raleigh, 2019).

• The Dutch Hunger Winter (1944–1945): Pregnant women exposed to famine during World War II had children who were more likely to develop obesity, diabetes, and metabolic disorders later in life (Roseboom et al., 2006).

• The Great Depression (1929–1939): Widespread food insecurity in the U.S. led to changes in dietary patterns and metabolic efficiency, influencing future generations’ susceptibility to weight gain and metabolic disease (Baum, 2017).

• The Atlantic Slave Trade (1600s–1800s): Enslaved Africans faced extreme food deprivation, and their descendants may carry epigenetic adaptations that favor fat storage as a protective measure against starvation (Francis et al., 2019).

• The Holocaust (1939–1945): Studies show that children of Holocaust survivors have altered stress responses and metabolic adaptations that could influence weight regulation (Yehuda et al., 2016).

Dieting and Food Scarcity as Modern Famine

While most of us in the U.S. don’t experience famine in the historical sense, many people still live in conditions of food scarcity—whether through chronic dieting, poverty, or systemic barriers to food access. The body doesn’t distinguish between an intentional caloric deficit (such as dieting) and an actual food shortage—it simply recognizes restriction as a threat and responds accordingly by slowing metabolism, increasing fat storage, and intensifying cravings for high-energy foods (Mann et al., 2007).

Beyond dieting, food insecurity itself is a form of modern famine. Millions of Americans, particularly those in low-income communities, experience food deserts—areas with limited access to affordable, nutritious food. In New York City alone, about 1.2 million people struggle with food insecurity, meaning they lack consistent access to enough food for an active, healthy life (Feeding America, 2023). Studies show that people who experience food insecurity are more likely to have higher body weights, not because of overeating, but because their bodies have adapted to scarcity by becoming more efficient at storing fat (Franklin et al., 2012).

Breaking the Cycle of Shame Around Body Size

Understanding that our bodies respond to restriction and scarcity by storing fat helps reframe the shame many people feel around their weight. Whether someone has dieted repeatedly, grown up in poverty, or experienced food insecurity, their body is not failing them—it’s doing its job to survive.

Rather than seeing weight gain as a problem, we can recognize it as a natural, biological response to real-life food struggles. This means shifting the focus from restrictive weight-loss tactics to ensuring consistent, nourishing food access and body-affirming care for all people—regardless of size.

Final Thoughts

If you’ve ever felt frustrated with your body for holding onto weight, I hope this helps you see things differently. Your body is not betraying you—it’s protecting you. Understanding the role of epigenetics, famine history, and diet culture can help us move toward self-compassion, body acceptance, and a more sustainable way of caring for ourselves.

Instead of fighting your biology, embrace the wisdom it carries. Your body is not the problem—diet culture and systemic oppression are.

References

• Strings, S. (2019). Fearing the Black Body: The Racial Origins of Fat Phobia. NYU Press.

• Yuan, V., Price, E. M., & Robinson, W. P. (2019). The impact of maternal nutrition on the epigenome. Nature Reviews Genetics, 20(7), 377-392.

• Mann, T., Tomiyama, A. J., Westling, E., Lew, A. M., Samuels, B., & Chatman, J. (2007). Medicare’s search for effective obesity treatments: Diets are not the answer. American Psychologist, 62(3), 220-233.

• Feeding America. (2023). Hunger in New York.

• Franklin, B., Jones, A., Love, D., Puckett, S., Macklin, J., & White-Means, S. (2012). Exploring mediators of food insecurity and obesity. Journal of Community Health, 37(1), 253-264.