A Doctor Explains the Obesity Epidemic and Why Ozempic Won’t Be the Answer for Most People.

11 min readOct 20, 2024

Half of Americans try to lose weight every year[i]. Unfortunately, most fail. Even worse, most of those who do lose weight soon regain it: within 5 years 80% of the weight lost has been regained.[ii]

It’s not surprising that so many Americans are trying to lose weight, because 40% of Americans are currently obese (BMI’s > 40). What is surprising is that this is a recent phenomenon: rates of obesity only began climbing 50 years ago, but alarmingly have tripled since then[iii]. And, unfortunately, this trend shows no sign of leveling off[iv]:

Of still greater concern, obesity has been increasing fastest among our children[v]:

Maintaining a desired weight improves health and extends life, so being overweight can be thought of as an important medical condition, like diabetes or heart disease. But somehow these other medical conditions that don’t seem tragic. Perhaps uniquely, trying and failing to lose weight seems tragic, because it can make people feel like failures: unable to control even their appetite, their lives seem out of control.

The Medical Model

The medical model for weight that I was taught in medical school 50 years ago went something like this: “calories in minus calories out equals fat gained”. And this was a quantitative relationship: every 3,500 excess calories became one pound of fat.

Calories In: The Simple Part

Unfortunately, while true, the above equation has not been helpful to patients trying to lose weight, because in practice doctors largely focused on “calories in” part of the formula, perhaps because this was easier to measure than the “calories out” part. As a result, this particular bit of medical dogma has aged poorly, because when patients failed to eat less, they were blamed by their physicians for their problem, a classic “blame the victim” scenario. This approach solved the doctor’s problem (“What do I do for a patient who needs to lose weight?”) by simply making it the patient’s problem. Unfortunately, this compounded the patient’s weight issue by adding another problem: “Not only am I overweight, but it’s my own fault.” In the clear light of hindsight, some doctors who blamed their overweight patients for their condition are now embarrassed by their failure to understand the nature of this disease, and especially by their lack of empathy. As Dr. Prescott Lee confessed in a recent Washington Post Op Ed: “Like many doctors, I was once condescending to obese patients. I regret it.” [vi]

The claim that weight is a matter of willpower makes little sense, of course, because Americans didn’t suddenly suffer a massive loss of “willpower” 50 years ago. Rather, something more general and systematic seems to have happened. It’s now believed that three changes in the American diet (the advent of ultra-processed food, sugar based soft drinks, and fast food) largely account for the obesity epidemic[vii], a view supported by the subsequent spread of the obesity to other countries as the American diet metastasized around the world.[viii]

Is it really possible that a change in diet can ruin a country’s health? Actually, yes. We saw just such a scenario play out in England in the 1800’s when sugar grown in the Caribbean became widely available and very inexpensive. Within a few decades per capita consumption in England soared from under 2 kg/year to 60 kg/year, with devastating public health consequences: tooth decay, type 2 diabetes, obesity, all conspired to shorten lives of the English. And the UK sugar tragedy continues today where per capita sugar consumption remains stubbornly high at 40 kg a year.

As the UK example shows, changing dietary custom,s even in the face of overwhelming health consequences, is slow and difficult. And then there’s this: as big a problem as sugar consumption is in the UK, it’s actually worse here in the US, where we have led the world in per capita sugar consumption since 1970. We Americans currently consume a shocking 70 kg of sugar per capita each year.[ix]

Assigning Blame Is Not a Treatment

Blaming patients for their weight was particularly unfair because one’s weight is not just about calories: dietary factors beyond calories can profoundly affect one’s weight, in particular the details of one’s diet, details that are determined by what foods are available as well as cultural and personal preferences. Lack of fiber, inadequate fruits and vegetables, and highly processed foods all are known to predispose to weight gain. Exactly why highly processed foods pose such a risk isn’t clear. It’s likely that because these foods are engineered by PhD chemists to be irresistible, calorie dense, and cheap these foods lead to what amounts to systematic overfeeding, recapitulating the same unfortunate results seen in subjects in overfeeding experiments. While this explanation seems almost too simple, a variety of lines of evidence converge on a simple truth: As Tamar Haspel puts it in a recent article in the Washington Post[x], “…food companies try to make their food irresistible and sell as much as possible! It’s their fiduciary responsibility.”

Note that highly processed food is much cheaper than a healthful diet of fresh food. The importance of “cheap” in the above list of factors driving the adoption of highly processed food is especially important for the many Americans who are food insecure. Thus, the dynamic may be not that people want to eat highly processed food, but that many people can only afford these foods. Tellingly, this association between poverty and obesity emerged over thirty years ago, and has only become starker over time.[xi]

Calories Do Matter

While the quality of one’s diet contributes to one’s weight, calories certainly do matter. When research subjects are systematically overfed by 60%, they reliably gain weight, although interestingly there is a great deal of variation in just how much weight subjects gain. Those resistant to weight gain automatically employed several strategies to offload unneeded calories, including moving about more or simply fidgeting. Resistant individuals were also able to increased their metabolic rate.[xii]

Calories Out: The Hard (Effortful) Part

The human body is a marvel of efficiency, but it does require quite a lot of energy at rest: circulating one’s blood, breathing, thinking, ongoing repair of body structures, and running the immune system, all require calories. This baseline rate of metabolic activity is called the basal metabolic rate (BMR) and is roughly 1 calorie/minute. Because these activities are required whether one is awake or asleep, sleeping reduces this baseline rate by only 15%. Exercising uses calories over and above the BMR, of course, but because the human body is so efficient exercising burns surprisingly few additional calories. For example, it requires only 100 calories (two Oreo cookies) to jog one mile. Because human fat is so energy rich (3,500 calories/pound) one would have to jog for a couple of days (35 miles) to burn one pound of fat. So, while there are many good reasons to exercise, exercise is an inefficient and time-consuming way to lose weight.

Despite the efficiency of the human machine, sustained muscular effort can over time can metabolize substantial amounts of fat, causing a steady and sometimes rapid weight loss. As an example: walking all day with a pack on the Appalachian Trail typically causes walkers to lose an average of two pounds per week, although some walkers lose as much as 5 pounds per week.[xiii] This suggests that less intense activities, if continuous, could also lead to weight loss. Indeed, even just fidgeting can help reduce weight and protect against obesity.[xiv] [xv]

The Body’s Set Point

We now know that while caloric input and outflow are important mechanistically, the body’s approach to weight is much more subtle and complex than simple caloric arithmetic, because the body has many hacks to fine tune its use of calories and thus its weight.[xvi] For example, in time of famine when calories are scarce the body can expend fewer calories supporting its immune system or maintaining its muscle mass. Conversely, when calories are abundant, the body can fritter away unneeded calories by fidgeting. How these mechanisms are coordinated is captured in the idea of a set point for body weight. We’re still learning about just how this “set point” is set[xvii], but a host of factors contribute: genetic endowment, epigenetic factors, early life nutrition, microbiome, stress[xviii], baseline thyroid hormone levels, adaptive thermogenesis[xix], even the recently described “thick sticky brain goo”[xx], all these and likely others contribute. Note that, while some of these factors influencing the body’s set point are set at birth (e.g. genetic factors) and some others change throughout life (e.g. microbiome, stress), few are actually conscious choices.

Hacking One’s Weight with Drugs

The history of using drugs to encourage weight loss goes back over a century. Nicotine has long been popular to help with weight control, despite the drawbacks that come with smoking. The first drugs specifically intended for weight loss were amphetamines. These drugs were noted to suppress the appetite in the 1930’s, and very quickly were adopted for weight control. By 1945 over half a million Americans were taking amphetamines. In the 1950’s combination pills that included amphetamines, barbiturates, thyroid hormone, and even diuretics were being sold, often without a prescription. While amphetamines are effective for short term weight loss, this comes with a host of side effects including addiction and cardiovascular problems. As a result, this party came to an end in 1970 when the federal government stepped in to regulate and eventually ban amphetamines for weight loss. Subsequent attempts at regulating weight with other drugs quickly failed: fenfluramine (“fen-phen”) was introduced in 1990, but withdrawn because they caused damage to heart valves. Sibutramine (Meridia) as approved in 1997, but withdrawn in 2010 because of cardiovascular damage.

The treatment of bodyweight has been again upended with the arrival of injectable GLP-1 receptor agonists. Originally approved in 2017 as a treatment for type 2 diabetes, Ozempic was soon discovered to reliably cause weight loss, and within a few years 6% of Americans are taking either Ozempic or Mounjaro at a cost of $1000 a month.[xxi] Surprisingly, we don’t yet have a clear idea of everything these drugs are doing. They certainly slow gastric emptying and reduce hunger as well as increasing insulin and reducing glucagon production. But they also somehow treat other conditions, including cardiovascular and chronic kidney disease, and may also be lowering the risk of colorectal cancer, pancreatitis, and even addiction and alcohol use disorders.[xxii] This uncertainty about what exactly these drugs are doing raises concerns when so many Americans are taking them, possibly for the rest of their lives. It therefore seems sensible to try other, less invasive, alternatives to help with weight control before accepting a lifelong injectable solution.

There Is No Optimal Diet

While there is no optimal diet, some diets are better than others. All successful diets have a few characteristics: First, it must be a diet that you enjoy and can stick with. Additionally, a well-done longitudinal study, The Pounds Lost Study[xxiii], found four other critical elements of a healthy diet. These included eating a diversity of foods, eating more protein and more fiber, and eating less ultra-processed foods. Importantly, not all ultra-processed foods are equally problematic, with sugary drinks and processed meat products being the worst offenders[xxiv]. When pressed for a baseline diet, the authors of The Pounds Lost Study suggested starting with the DASH diet[xxv] or the Mediterranean diet.

Calories Out Reconsidered: Other Approaches to Changing Caloric Balance

Adopting a healthy diet is the essential first step toward an optimal weight and may be all that most people require to dial down their caloric intake. But, for those who find this single step insufficient or simply want to go further there are other strategies that can be added that increase one’s caloric burn rate. The strategies used by the research subjects who were intentionally overfed included simply moving around more and fidgeting[xxvi], and these strategies are available to all of us. Epidemiologists endorse this approach by recommending that we sit for no more than 30 minutes before taking a brief walk, an approach that not only burns more calories but also shifts one’s metabolism to a healthier mode.[xxvii]

Unfortunately, getting up for a 5 minute “movement snack” every 30 minutes involves 16 interruptions in a work day, more than most of us (or our employers) find convenient. Another way to encourage more movement is to make the act of sitting itself slightly more effortful. So called “active sitting” requires a chair that has a slightly unstable sitting surface, but such chairs can increase basal metabolic rate by 20% to 40%[xxviii], adding the equivalent of 3,000 steps over the course of an 8-hour workday. Active chairs are available from a number of companies: CoreChair in Canada, MiShu and Swopper in Germany, OOR360 in the United States, as well as others. (Full disclosure: I’m the founder of QOR360.)

Everyone’s Path to Caloric Equilibrium and A Healthy Weight Will Be Different

For 3 million years we humans controlled our weight without Ozempic, so it’s unlikely that 40% of Americans will need this drug to maintain a healthy weight. Epidemiologic evidence suggests that the epidemic of overweight people has its origins in the radical change in our diet that began several decades ago. We now understand that the quality of one’s diet is crucial to maintain a healthy weight, perhaps even more important than quantity of calories. While it’s difficult to change dietary habits that are cemented during childhood, for most people this will be the best starting point, because absent a wholesome diet, restricting calories by dieting generally fails. Hacks to burn more calories such as exercising, taking frequent breaks for “movement snacks”, fidgeting, and sitting actively can all contribute to better health, and over time can also help with weight reduction.

It was hoped that Ozempic and its elk would be a simple solution to the obesity epidemic, but it turns out that as H. L. Mencken may have said: “For every problem there is a solution that is simple, neat — and wrong.” It turns out that there simply is no “magic pill” for weight control. Ozempic has well known downsides (cost, lifelong treatment), and more problems are emerging. A recent paper in the prestigious medical journal JAMA[xxix] reports increased risks of pancreatitis as well as complications associated with general anesthesia. Increased rates of blindness have also been associated with Ozempic[xxx]. Perhaps most worrisomely, instances of suicidal thoughts and self-injury have also come to light. Our mass experiment with Ozempic has already caused difficulty for some patients, and we don’t yet know the complete spectrum of problems that will appear. So, for the foreseeable future the natural approach to weight control of eating healthy and moving more will remain the best option for most people who want to control their weight.

[i] https://www.cdc.gov/nchs/data/databriefs/db313.pdf

[ii] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5764193/

[iii] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10106700/pdf/fspor-05-1122938.pdf

[iv] https://www.niddk.nih.gov/health-information/health-statistics/overweight-obesity

[v] https://www.niddk.nih.gov/health-information/health-statistics/overweight-obesity

[vi] https://wapo.st/3BHYEWp

[vii] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611578/

[viii] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611578/

[ix] https://plotly.com/~vizthinker/13/sugar-consumption-of-top-25-gdp-countries.embed

[x] https://www.washingtonpost.com/food/2024/09/20/ultra-processed-foods-obesity-reasons-overeating/

[xi] https://www.nature.com/articles/s41599-018-0201-x.pdf

[xii] https://pubmed.ncbi.nlm.nih.gov/10578199/