8.3: Regarding obesity, we have at least two controversies

Regarding obesity, I am aware of at least two major controversies:

1. Is obesity itself (or body fat) dangerous to health, or is obesity just a side effect of other health risks like sedentary lifestyle, stress and poor nutrition? Those risks could be addressed to improve health, without necessarily seeing a change in body weight.
2. What can we do to improve the health of people who are already fat? Is weight loss the solution, or another danger to health?

In this chapter, we will explore the first one in some depth. Since public health is so much about going upstream to address the causes of disease, the first controversy about the causes of ill health is perhaps the driving question. However, since so much attention is placed on weight loss, as a personal health, public health, and medical question, it is also important to discuss the second.

To start with, let's briefly consider the frequent proposed solution to obesity -- dieting for weight loss.

News flash: Dieting usually doesn't work

Some people think that "fat people should just lose weight." It's not that simple. What is their access to good nutrition and activity? Does dieting work in the long term? Is it healthy? Is a fat person who loses weight going to have the same health outcomes as a person who has been thin all their life?

There is good evidence that dieting does not work over the long term for most people. The vast majority of people who diet regain the weight they lost. For those who maintain weight loss, their metabolism is usually NOT the same as that of a person who was never fat -- meaning that they have to work harder than a thin person would to maintain that lower weight.

New weight loss drugs (see ADD PAGE) do often work for sustained weight loss for those who can afford them, tolerate the side effects, and persist in using them for years. Most people using Ozempic or Wegovy lose about 12-15% of their body weight over a 16-month-period if they combine it with dietary changes -- for someone weighing around 200 pounds, that would mean a 30-pound loss. That may have positive effects on blood pressure, blood sugar, or arthritis symptoms and can result in a meaningful improvement for health. It would not mean that everyone fits into the "normal weight" category of a BMI chart after using weight-loss drugs, nor that they fit some societal standard of thinness determined by fashion. Population health implications of these new drugs are being studied now -- it's unclear how large an effect they may have on rates of diabetes, high blood pressure, or other ailments.

Optional Articles on this Subject

While some of these articles are older, they still offer an important perspective on the links between fat, fitness, and health.

"The Fat Trap," from the New York Times
This article discusses how people maintain significant weight loss, often with great difficulty.

"At a Glance: Nutrition, Physical Activity and Obesity" This webpage makes the link between chronic disease and nutrition and physical activity. It highlights trends in obesity, and it emphasizes what the CDC is doing about it.

Can you be fat and fit, or thin and unhealthy? This article adds a few more layers to the obesity debate, making a distinction between those who are "metabolically healthy" and "metabolically unhealthy".

CNN: 'Fat but Fit' Is a Myth...
This article highlights a study that shows for people at ALL weights, more physical activity improves cardiovascular health. It also shows that who are obese are more likely to develop heart disease than those who are thinner, when you compare people with the same level of physical activity. This suggests that everyone should stay active/fit AND that obesity is still a health risk, even among those who are active. The article also includes (near the end) the views of a couple of researchers who critique the study and come back to affirming the evidence for the "fat but fit" idea. As you can see, science evolves over time through both data and debate -- and it can take a lot of studies and a lot of time to reach a new consensus on health.

There is consensus, however, that good nutrition and physical activity are good for everyone's health, regardless of weight.

Both thin and fat people benefit from good nutrition. Both thin and fat people benefit from some level of physical activity. Regardless of whether it leads to any change in weight. Good nutrition and physical activity -- like sleep and stress reduction -- have independent effects on health, apart from any influence they have on body size.

I have noticed that people often start talking about nutrition, then switch to talking about weight as if it were the same thing (or vice versa - they start talking about weight and blend it with nutrition). Of course, there is a relationship among nutrition, physical activity, and weight -- but they actually are not the same thing!

In this Chapter...

In this chapter, I present some of the data and arguments on both sides of the controversy about obesity's effects so you can reach your own conclusions.

New research in the coming years should improve our understanding of the health impacts of weight, resolving the controversy or finding common ground. At the moment, though, you should know that it is under debate.

• First, I present some information on rates of obesity and overweight -- the undisputed fact that Americans are larger now than they were in the past.
• Then, I present the mainstream view of obesity as a serious health crisis.

• Then, I introduce you to some of the arguments of the "obesity skeptics" and the analysis of how weight stigma (or bias) has a significant effect on health.
• Then, we take a closer look at the many factors that contribute to obesity in the population as a whole.
• Then, this module offers a brief look at strategies to promote access to good nutrition and physical activity, resources that improve health regardless of weight or size.