World Anti-Obesity Day is on November 26th every year. This year it just so happens to fall on our Thanksgiving Day. How fitting is that? Although it would be better fitting with elastic pants! Okay, sorry, bad pun. All joking aside though, obesity has become a global problem over the last few decades. And when we say global, we mean every part of the world except sub-Saharan Africa.


According to the WHO (World Health Organization), obesity worldwide has nearly tripled since 1975 and increased about five times in children and adolescents. In 2016, this equated to nearly 40% of adults being overweight, and 13% classified as obese. And in 2019, 38 million children under the age of 5 were either overweight or obese. This is the same as the metro area population of Tokyo! Yet, it gets even worse: when we group adolescents older than the age of 5, we see 340 million adolescents who are either overweight or obese. And this, my fellow Americans, is more than the entire population of the United States!!! Clearly, we have a global and complex public health concern. 


How Did This Happen?

Why has obesity been on the rise throughout the world? There are several factors that contribute to obesity, both internal and external. And you might even be surprised at a few of them.



The human body is designed to protect itself in all sorts of ways, including from starvation. This means that when there’s an opportunity, we have hardwired ways of holding onto excess body fat. Our body doesn’t know that we live in the land of plenty and errs on the side of caution that it might be several days before our next meal. How does our body increase fat storage? By telling us to eat. 

There are two important hormones that come into play: leptin and ghrelin. Leptin is released by our fat cells and sends signals to the brain about on much fat is being stored. The higher our leptin levels, the more fat we are storing, and the more overweight we become. Leptin also tells us that we are full so that we (ideally) stop eating. 

Once fat reserves fall and leptin levels are low, the brain starts believing that it’s starving and releases the hormone, ghrelin. This is often called the hunger hormone as it signals the feeling of hunger so that we begin eating again. In this way, our body can maintain a healthy weight. 

A problem occurs when a person is overweight or obese. When a person stores fat in excess, their leptin levels remain constantly high. This should be telling our brain that we have maxed out our fat storage and to limit our calories, but that’s not the way it works. When leptin levels get too high for too long, our body develops leptin resistance. Leptin resistance is now considered one of the main contributors to obesity, biologically speaking. This is when our brain doesn’t get the message. It becomes resistant to all the leptin signals and thus resistant to feeling full. In essence, our brain doesn’t see that we’ve become fat. It signals us to eat more and reduce energy expenditure. 

People with leptin resistance have a hard time keeping weight off as they are fighting against their leptin signals, essentially playing tug-of-war. The key to reversing leptin resistance is to overcome our biology with committed and long-term lifestyle and dietary changes.


Genetic Factors:

It is said that our genes account for between 40% and 70% of our likelihood of developing obesity. Through decades of genetic research, scientists have identified which genes contribute to the risk of obesity (and there are hundreds of them). Taken individually, these genes each don’t contribute much, but when a person has all these genes turned on then the collective contribution significantly increases risk. This doesn’t give us the excuse to blame our body weight on our genes, however. Our genetics are only part of the picture. 

The way we interact with our environment impacts our genes far more than previously thought. All external inputs are able to switch genes on and off. A healthy diet, plenty of exercise, low stress, low toxin burden, and positive relationships can all switch off genes that increase disease risk while switching on genes that protect against disease. Amazing, huh? We are not a product of our parent’s genes as much as we are a product of our own creation.


Mental Health:

Some mental health disorders can have symptoms that lead to weight gain. Examples include decreased sleep (and excessive sleep), lethargy, and increased appetite. The reverse is also true, where weight gain can lead to mental health issues. Those who struggle with high blood sugar and insulin resistance (and thus likely to be overweight) have decreased growth of brain cells, incorrect wiring of brain cells, and increased stress hormones. These all lead to mental health disorders like depression and anxiety and cause a “chicken or egg” effect of perpetual cycling.

Furthermore, some medications meant to treat mental health disorders have actually been associated with moderate to severe weight gain. 

Lastly, on the genetic level, those with genes coded for high BMI are at a greater risk for having depression.



Of all environmental inputs, the food we eat has the most impact on whether a person becomes overweight or obese. This has become increasingly more true as processed foods are now being seen across the globe as they undermine traditional diets. Processed foods are stripped of nutrients and then altered with additives and preservatives to create a product that resembles food. They are cheap to make, designed to be addictive, widely available, affordable, and heavily promoted. It is far too easy to overeat when the food you’re eating is processed. They are manufactured to have desirable tastes and textures, leading to increased appetite and high reward value. Since they are cheap to make and cheap to buy, processed foods are able to enter all communities, all incomes, and all nationalities. Oftentimes, these foods are the only options available for those living in rural or remote areas with no nearby grocery store. This explains the explosion of diabetes and obesity in Indian reservations and other remote or rural areas.


Life Events:

Environmental inputs other than diet also influence our propensity towards weight gain. Even before birth, the nutrition and health of a fetus are affected by their mother’s diet. A person can therefore be more susceptible to weight gain and obesity throughout their life if their mother had an unhealthy diet while pregnant. 

It goes without saying that weight gain can result after a pregnancy. On average, women gain two pounds after the birth of each child, which then adds up with multiple children. On the other side of the spectrum, women in menopause are also more likely to gain weight (and to have it redistributed into an “apple shape,” associated with diabetes risk). 

Throughout life, people fall into a comfortable routine. Statistically, this routine embraces a sedentary lifestyle, poor sleep habits, and high levels of stress. Each of these habits can cause weight gain and obesity over the years. 

Several chronic diseases are either brought on by obesity or weight gain (among other factors) or can cause obesity. Examples include diabetes, cardiovascular diseases, PCOS, thyroid imbalances, kidney problems, and more. Lowering your risk of chronic disease will further protect you from obesity. 

Lastly, some medications can increase appetite and lead to weight gain. These include select antidepressants, mood stabilizers, diabetes drugs, steroids, beta-blockers, and allergy relief meds.



Poor quality sleep or not enough sleep both greatly contribute to weight gain and obesity as well as depression and cardiovascular disease risk. Sleep problems disrupt various hormones such as cortisol (stress hormone), ghrelin (hunger hormone), and leptin (satiety hormone). Imbalances of these hormones can lead to overeating and craving sugary, salty, or fatty foods. Developing healthy sleep habits and techniques to deal with stress can help increase energy, normalize appetite, cut cravings, and feel better overall. 


Access to Healthcare:

Obesity is a complex and chronic disease often causing additional chronic diseases while robbing our quality of life. It is imperative to have affordable access to providers who can treat obesity using several tools at their disposal. Obesity requires individualized treatment to address the underlying causes and will always include diet modification and exercise habits. Other treatments would include behavior therapy, self-management tools, specific medications, supplements, and even surgical intervention. This comprehensive treatment approach to obesity is not readily available for many people. Factors such as clinician shortages in smaller communities, inadequate resources in low-income areas, transportation barriers, insufficient healthcare coverage, or inadequately trained clinicians, are all common issues facing those who aren’t under a doctor’s care. 

When it comes to something as complex as obesity, medical schools must focus their curriculum on disease awareness, early diagnosis, underlying causes, health education during pregnancy, whole-food nutrition, appropriate exercise, and psychological support. Until such a multidisciplinary approach is offered in med schools, those with obesity must seek out the best level of care they can reach. This is often found in functional or integrative medicine physicians, holistic health coaches, or trained nutritionists.



Perhaps the largest factor behind obesity that most easily goes unnoticed is marketing. Marketing is seen everywhere we look. It’s the bright-colored packaging, smiling cartoons, feel-good health claims, fit and thin actors, catchy songs, flash sales, and even proper lighting. If there is money to be made, there is a marketing team at work behind the scenes. 

There is significant evidence that marketing influences food consumption choices, and that those choices are part of a poor-quality diet. Why isn’t marketing associated with a healthy diet? Because there’s no money to be made there. This is why nobody can name a single song about carrots but everybody knows the Oscar-Meyer Weiner song. Songs tap into our emotions and motivate us to change. It is marketing at its best. 

Another reason why processed foods seem to have the most marketing is that there are huge industries making sure their products get into our hands. The sugar industry, dairy industry, meat industry, and agricultural industry all invest in vast amounts of marketing research. They are dialed in and know how to speak to our emotions, habits, and motivations. The key is to recognize when you’re being marketed to and have the tools to distinguish between nutritious food and feel-good food. Our earlier blog on reading nutrition labels addresses exactly that. Read it here.


Obesity has become a global problem and a public health crisis. It has reached the hard-to-reach corners, from young children to those living in rural areas. It is not bounded by social strata or education. Obesity has several underlying causes and is quite a complex disease. Some roots of obesity include biology, genetic factors, mental health, diet, life events, sleep habits, healthcare access, and clever marketing tactics. Many of these factors can be reversed and improved with lifestyle habits and increased awareness. Make it your goal to address the factors that most describe you and consciously choose to turn it around.