Fat Doesn’t Deserve Its Bad RapNEWS | 28 March 2025We starve it. Sweat it off. Freeze or carve it out. We claim that two thirds of Americans have too much of it, and then we take weekly injections just to shrink it. Body fat is generally demonized, and the way we treat people with larger bodies fills me with wrath. We build tiny airplane seats and complain when people can’t fit in them; we watch as total strangers mock and “concern troll” larger people about their health, for daring just to exist. We push people to feel shame for a body part some of us think is too large.
The way we stigmatize fat is especially galling given how important our fat cells are. One type secretes hormones that affect metabolism, while others help keep us warm. Where fat sits in our body provides support and structure, from arteries to anus.
We are used to thinking of fat as this passive thing we try to stuff into our jeans. But what if we saw it as it is: a biological organ and one of the most adaptable in the human body? Adipose tissue communicates with the gut, brain, immune system and more to keep us moving and healthy. What if we gave it the same research funding, care and attention we gave our hearts, livers or brains? Knowing us, we’d probably use the knowledge to make more drugs to get rid of it. But maybe we could reduce stigma and shame, and find value in our flexible and fascinating fat. And then we’d be a little less eager to throw it away.
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It might seem odd to think of fat as an organ, in part because many of the organs we think about are so contained. There is only one liver, only two kidneys. But adipose tissue is stored all over the body. The most abundant form, white adipose tissue, lives partially in places like the omentum, folds of connective tissue that form a fatty, protective apron over the organs in your abdomen. Most white adipose tissue—80 percent of our total fat mass—is subcutaneous, or beneath the skin, and tends to be concentrated in the stomach, hips, butt and thighs.
We wrongly associate this tissue with laziness. Instead, it is full of energy. Each cell contains a large droplet filled with multichained molecules called triglycerides, which it releases as fuel. White adipose tissue’s ability to grow and shrink is a feature, not a bug. It is constantly swelling and draining, taking up energy and sending it out again multiple times per day. Thanks to fat, our biochemistry hums along smoothly.
It's taken us a long time to see fat as a dynamic organ that isn’t just squishy storage for extra calories. About 30 years ago, with the discovery that it releases the hormone leptin, scientists finally began to understand fat as an actual organ. Leptin tells our body, “Hey, we have enough stored energy—no rush to get more.” In the years since, we’ve learned that white adipose tissue secretes other hormones and immune signals. It helps to regulate metabolism, promote insulin sensitivity, and increase or reduce inflammation.
But we don’t just have white fat; there is also brown adipose tissue, concentrated in the neck and armpit, around the trachea, lining the blood vessels, surrounding the kidneys, and more. While white adipose tissue has one large fatty droplet, brown tissue has many tiny droplets, and lots of mitochondria. It is thermogenic, increasing energy use to keep us warm. These relatively small fat depots can increase energy expense in humans by between 40 and 80 percent—running hard to make sure we run hot.
And in between there is beige fat. This adipose tissue starts white, but if it’s constantly exposed to cold temperatures, some of it decides on a career change. It makes more small fat droplets—and becomes capable of creating heat. These beige fat cells can then convert back to white fat cells when summer comes again.
Fat is versatile. In bone marrow, it helps bone cells turn over and generate new blood. Fat lines the outsides of our blood vessels, giving them support and helping to regulate dilation. Fat pads in our knees spread the weight of our body over our lower legs and help control blood flow in the area. In our anus, fat pads are essential to maintain fecal continence.
So why have we hated it so much and for so long? Fat phobia has existed throughout history, with even Shakespeare telling fat jokes, long before we understood anything about metabolic health. Now we associate a lot of visible fat on people as something unhealthy. But this fat we can see is not necessarily the fat we should care about. Overall fat mass is correlated with disease, but correlation is not causation. In fact, white adipose tissue that expands easily can protect against diabetes—one of the diseases most people fear they will get if they carry too much fat. But it’s the invisible visceral fat, particularly around the heart, that is most associated with cardiovascular problems.
Even how adipose tissue grows matters. Individual fat cells can grow larger if they become too full of triglycerides. This is linked to inflammation and metabolic syndrome. But adipose cells can also divide without ill effects. In both cases, the tissue is getting bigger, and a person is growing larger. But only one is linked to poor health. Increasing brown and beige fat in mice can actually decrease overall fat mass and increase how sensitive bodies are to insulin.
Because of this, measures of simple size, whether body mass index, waist measurement or anything else aren’t a reliable predictor of health. Around 32 percent of people designated “obese” are metabolically healthy, and around 24 percent of “normal weight” people are not.
But diets or drugs don’t focus on brown fat levels, or fat around the heart. While new drugs like GLP-1 agonists have wonderful effects on insulin resistance, most of their skyrocketing popularity isn’t because they can treat type 2 diabetes, which is what many of them were developed to treat. Instead it’s because of how much weight people on these drugs can lose—whether or not that weight changes someone’s health at all.
Diets and weight-loss drugs are marketed with health halos. But the real drive to lose weight is the societal stigma around this organ. There are plenty of studies showing that weight stigma has its own harms—and that the stress associated with it is, ironically, associated with weight gain.
Diets and drugs sell the public on “losing weight,” without regard for which kinds of tissue are being lost, or how that loss might affect the rest of the body. The hatred we have for other people’s adipose tissue affects how we treat them, and what we as a society demand people who carry more fat will tolerate to lose it. While a male contraceptive pill can be pulled from trials for low mood and acne, side effects like nausea, diarrhea, malnutrition, bleeding and more are considered normal and appropriate prices to pay for various forms of weight loss.
We would never treat our heart, liver or brain in such a way. We see these organs as complex, with positive and negative effects through the rest of the body—effects that need to be carefully considered every time we attempt to treat a condition. Fat deserves the same consideration.
Our stigma causes harm, and it also causes incuriosity. What do we lose by not considering the benefits of fat? What scientific questions are understudied or even ignored in our haste to label body size alone a disease? If we approach our squishy organ with more appreciation, we might be able to develop more treatments that target the metabolic disease and inflammation itself, rather than assuming less weight will solve all problems. We might learn more about how our own bodies use adipose tissue. We might gain a different view of larger bodies. We might do better for science and society, if we could only stomach a different view of fat.
This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.Author: Bethany Brookshire. Source
