If Obesity Is Officially a Disease, Let’s Treat It Like One

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An Obese Man Running and Sweating.Obesity was officially classified as a disease in 2013.

Under the belief that this new classification would improve health outcomes, the American Medical Association (AMA) decided to recognize obesity as a chronic disease.

As a result, the scientific community is increasingly thinking of obesity as a complex and chronic condition that requires well-considered intervention.

However, is this message coming across to the general population who are trying to lose weight?

The question is; if obesity is such a complex condition, why do we often over-simplify it by solely focusing on “eat less and move more”?

This article examines some of the limitations with traditional weight loss advice and looks at how we can make progress.

Why Is Obesity a Chronic Disease?


Despite traditionally held views that obesity is a kind of lifestyle choice with ties to gluttony, the condition is a complex one. 

To get away from this stigma and blaming, the American Medical Association and other health agencies now officially consider obesity to be a chronic disease (1).

It is undoubtedly true that obesity is complicated, and it is not a simple matter of eating less and running around more.

For instance, people who are obese have higher levels of hormones that encourage fat accumulation. Also, satiety signaling hormones do not work as effectively in people who are overweight (2, 3, 4, 5).

Unfortunately, this has the adverse effect of increasing fat gain and heightening appetite at the same time, which can result in overeating.

This overeating then causes worsening obesity, which makes exercise more difficult, and leads to decreased mobility and more weight gain.

In other words; obesity can be a perpetual negative cycle that is difficult to break, and only telling someone to eat less is both ineffective and unhelpful.

Complications of Obesity

An Infographic Showing Diseases and Medical Conditions Related To Obesity.

Although obesity does not directly kill, it significantly increases the risk of mortality.

Statistics estimate that obesity-related conditions lead to hundreds of thousands of deaths per year in the United States alone.

These conditions include (but are not limited to) certain cancers, heart failure, and stroke, which all share strong associations with obesity (6, 7).

The prevalence of obesity tripled between 1975 and 2018, and currently affects upward of 650 million people around the world (8).

Key Point: Obesity is officially recognized as a disease, and it kills hundreds of thousands of people every year.

But Isn’t Obesity a Lifestyle Choice?

There are indeed doubters to the wisdom of classifying obesity as a disease.

Some people believe that obesity is more of a risk factor, somewhat similar to smoking.

For instance, smoking itself does not kill. Instead, it may lead to lung cancer, which is often fatal.

This opinion does seem like a fair argument.

Similarly, obesity itself does not kill, but it can eventually cause cardiovascular disease or obesity-related cancers, which can.

It is also true that eating behavior is mostly a free choice; we can choose to eat what we want, and nobody is forcing anyone to overeat.

However, we are all human, and what we want to do does not always reflect our behavior.

Furthermore, all these ideas about obesity being a “choice” completely ignore the effect that hormones have on eating behaviors.

Nobody wants to be overweight or obese.

People do try (and fail) with diet after diet after diet to lose weight, and people who are almost starving themselves on restrictive diets did not choose to be obese.

It is, therefore, unfair, inaccurate and discouraging to call obesity a “lifestyle choice.”

Key Point: Calling obesity a “lifestyle choice” is ill-considered, and it does nothing to help people trying their hardest to lose weight.

The Limitations of CICO (Calories In, Calories Out)

A Man's Hand Holding a Calorie Counting Diet Smart Phone App.If we truly look at obesity as a disease, then we need to look at the actual cause of the problem.

Once we understand the causal factors, then we can work on finding an individualized solution.

At this point, there will be some people thinking like this;

“Losing weight is simple. If you just eat fewer calories than you burn, weight loss will follow”.

All true, for the most part.

The trouble is; if it were that simple, 39% of us wouldn’t be either overweight or obese right now (8).

To put it a different way; consuming fewer calories is important, but it is the “how” that matters most.

The Difference Between Counting Calories and How To Consume Fewer Calories

Counting calories first became popular in 1918 thanks to a best-selling diet book.

Since the obesity epidemic is a modern phenomenon, this shows that calorie counting is far from necessary to achieve a healthy weight.

At the same time, balancing calories is undeniably important, and it is anti-scientific to state that calories do not matter.

They do.

But simply telling dieters to count how many calories they consume and to burn more than they eat is not the answer.

Instead, we need to look at the necessary behaviors and hormonal factors that encourage a healthy eating pattern.

For instance, a diet that promotes and encourages satiety naturally leads to a better energy balance.

Calorie counting can be a useful dietary tool, particularly if the individual does not have a strong knowledge of the nutritional properties of various foods.

However, it is not the be all and end all of dieting, and for many people, it is not even necessary.

Key Point: Energy intake is unquestionably important, but it is critical to consider the behavioral and hormonal aspects that enable a better energy balance.

How Hormones Influence Overeating

Infographic Showing How Hunger Hormones Ghrelin and Leptin Affect Obesity.

There are numerous hormones involved in obesity, and some of these include;

  • Estrogen
  • Ghrelin
  • Growth hormone
  • Insulin
  • Leptin
  • Testosterone

Among these hormones, the two worth paying particular attention to for weight loss are leptin and ghrelin.

Leptin and ghrelin are known as ‘hunger hormones’ because they regulate hunger.

These hormones can either encourage feelings of fullness or increase our appetite.


Ideally, we want to have sufficient leptin levels since this hormone keeps us feeling full.

However, leptin levels are generally lower in obese individuals, and leptin tends to decrease as people lose weight.

How Leptin Works

Leptin’s mechanisms are an extensive topic, and the hormone interacts with a wide variety of energy regulators in the body (9).

To briefly summarize; leptin sends chemical messages which activate receptors in a region of the brain called the hypothalamus.

Once this happens, the release of neuropeptide Y and anandamide, two compounds that promote hunger, is inhibited (10, 11).

Additionally, activating the leptin receptors stimulates the production of a-MSH, which directly suppresses hunger (12).

Concerning its effect on dieting, we can view leptin as a “good” hormone; it encourages satiety and sensible eating patterns.


To put it simply, we can view ghrelin as the “anti-leptin.”

In other words; ghrelin has the complete opposite effect of leptin, and it can promote hunger and unhealthy eating patterns.

For instance, higher ghrelin levels are associated with constant food cravings and eating disorders such as binge eating (13, 14).

How Ghrelin Works

Diagram Showing How Ghrelin and Leptin Affect Our Appetite.

Ghrelin release triggers receptors in the hypothalamus that promote hunger, and it also activates “reward pathways” that encourage eating (15).

Animal studies and clinical trials on humans confirm that ghrelin has an impact on overeating.

In these studies, ghrelin injections increase food intake in a dose-dependent manner; the more ghrelin, the higher the food consumption (16).

Key Point: The hunger hormones ghrelin and leptin help to regulate energy balance. Leptin promotes satiety and leads to lower food consumption, and ghrelin increases hunger and often results in overeating.

Overall Lifestyle is the Way To “Treat” Obesity

As shown above, hormones have a significant influence on our satiety levels.

If someone is trying to lose weight and only considers the idea of “eating less and moving more,” then it is unlikely that sustainable weight loss can follow.

For example, combine a typical salad-based, low-calorie and low-protein diet with running for hours on a treadmill each day.

The result?

Ghrelin levels up, leptin levels down, an unrewarding diet, and constant hunger.

Such frustration is only sustainable for so long.

In reality, we need to consider every lifestyle aspect carefully.


  • Protein is the most satiating macronutrient, so sufficient protein intake is essential. Also, high-protein meals tend to influence hunger hormones positively. For example, one study shows that a high-protein breakfast decreases postprandial (post-meal) ghrelin release more than a high-carbohydrate meal does (17).
  • In addition to protein, the rest of energy intake can come from fat and carbohydrate in a ratio depending on the individual’s personal preference. Many people do well with a lower carb, moderately high protein diet, but others may do better with lower or higher carbs.
  • Carbohydrate sources should ideally emphasize fibrous carbs. Fiber is more satiating than simple starches and sugars (18).
  • For some people, sugar and refined carbohydrates, particularly in combination with fat (e.g. donuts, pizza) are “trigger foods”. If someone has an unhealthy relationship with food, the “moderation” message doesn’t work, and these foods can trigger overeating and ruin progress (19, 20).
Key Point: Protein is the most satiating macronutrient, and it is important to consume enough. Refined carbohydrates and sugar are the least satiating foods, and should ideally be limited.


It may not be a common consideration, but the quality of sleep plays a significant role in obesity (and weight loss).

  • Remember ghrelin and leptin? Well, short sleep duration reduces circulating levels of leptin and increases ghrelin. In other words, lack of sleep can encourage food cravings and unhealthy eating patterns (21, 22).
  • Research demonstrates that sleep restriction hinders weight loss in obese patients (23).
  • In a randomized, clinical trial of a weight loss program, sleeping more than 7 hours per night increased the likelihood of successful weight loss by 33% (24).
Key Point: Sufficient sleep is important for optimizing the level of hunger hormones, and better sleep is associated with successful weight loss.


There are many different opinions on exercise and weight loss, but there are two common views which we can often hear.

One states that you have to burn more calories than you consume, and weight loss will follow.

The other proclaims that “you can’t outrun a bad diet”.

While both of these statements are somewhat true, combining a healthy diet with an exercise program is the best option.

For one thing, exercise has a whole range of health benefits irrespective of energy balance and weight loss.

That said, exercise undoubtedly helps with losing weight too;

  • Research shows that resistance training can increase the resting metabolic rate in the medium-term (25, 26).
  • In a randomized trial, results suggested that an 11-minute session of resistance training increased energy expenditure over a 24-hour period (27).
  • A randomized trial demonstrates that combining resistance training with dietary intervention leads to greater fat loss than only diet. Additionally, it leads to increases in lean mass (28).
Key Point: Combining exercise with a healthy diet is more effective than diet or exercise alone.

Final Thoughts

Eating less, moving more and consuming fewer calories all do help with losing weight.

However, these are the results of a healthy lifestyle, and just telling someone to exercise more and eat less can often be unhelpful.

Beating obesity requires three things; motivation, an unquestionable resolve to succeed, and the knowledge necessary to do so.

To sum up; calories are important, but enabling sustainable weight loss is more about the factors that encourage and promote this desired behavior.

According to the American Medical Association, obesity is a “chronic and complex disease.”

In that case, why is it so rare that people trying to lose weight are aware of these complexities?

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