Tall, Short, Fat, and Thin

Thin Privilege from Skinny Genes

New research in PLOS Genetics provides deeper insight than ever into the role that skinny genes may play in protecting an individual from obesity. Senior investigator Sadaf Farooqi sums it up:

This research shows for the first time that healthy thin people are generally thin because they have a lower burden of genes that increase a person’s chances of being overweight and not because they are morally superior, as some people like to suggest.

It’s easy to rush to judgement and criticise people for their weight but science shows that things are far more complex.

We have far less control over our weight than we might wish to think.

Comparing DNA in Thinness, Severe Obesity, and Normal Weight

Researchers from Cambridge analyzed DNA from 1,622 thin subjects, 1,985 subjects with severe obesity, and 10,433 normal weight subjects. Researchers have understood for some time that obesity is highly heritable. Heritability of obesity is roughly 70%.

But what this study adds is an understanding that thinness, too, is highly heritable. Three out of four people (74%) in the cohort of thin individuals had a family history of being thin and healthy. The team found new genetic profiles that were significantly more common in thin people. Investigators hope that these genetic insights will point the way to new treatments for overcoming obesity.

An Inheritance of Thin Privilege

If you want a real understanding of thin privilege, talk to someone who’s had bariatric surgery. These folks have lived on both sides the body size apartheid system that operates quietly and powerfully in our culture.

When you’re big, people dismiss you in so many ways – employment, healthcare, education, personal relationships, even casual interactions. Author Roxane Gay describes one such experience in a moving essay:

After more than 15 years of refusing it, I made the decision to get weight-loss surgery on an ordinary day. At home in Lafayette, Indiana, a young man yelled at me to move my fat black ass while I was crossing a grocery store parking lot to my car. It was the last straw.

I had to accept that I could change my fat body faster than this culture will change how it views, treats, and accommodates fat bodies.

After surgery, people will tell you that the difference in how they are treated is profound. And profoundly wrong. You are not suddenly a better person because you are thinner. You are not a lesser person when you are heavy. The difference is physiology. The human body regulates its stores of energy – fat mass – with exquisite precision. Genes guide that process.

It’s nothing new. Humans discriminate based on physical differences. Skin color, weight, and other features come into play. But we now know that thin privilege is an unearned privilege, just as fat discrimination is unjustified.

Perhaps with knowledge, we can gain more respect for human diversity.

Click here for the study and here for more from the BBC. For more on thin privilege, click here.

Tall, Short, Fat, and Thin; photograph © Leonora (Ellie) Enking / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


January 27, 2019