Obesity and Diabetes: Separating Fact from Fiction

Dr Jedha, Host

Hello, Dr Jedha here and thanks for joining me. If you’re here, chances are you’re looking for ways to improve your blood sugar, lower your A1c, and maybe even reduce the medications you’re taking. You’ve probably heard things like, ‘You need to lose weight to manage diabetes,’ or, ‘Obesity is the cause of type 2 diabetes.’ But is that really true?

Being it is World Obesity Day when this episode is going live, it seems like a great topic to explore, so today, we’re breaking down the science behind the link between weight and diabetes, and we’ll also tackle some of the biggest myths and misconceptions—like whether everyone with diabetes is overweight or if weight loss is the magic fix. It’s all very interesting to explore.

01:56

First, let’s set the stage with some key facts. Globally, more than 2.5 billion adults are classified as overweight, and of these, over 890 million are considered to be living with obesity. That’s roughly 16% of the world’s adult population. In just a few decades we’ve seen rates of obesity double. Unfortunately in children, rates have quadrupled.

So why are we seeing such a sharp rise in obesity rates around the globe? The answer lies in what researchers call an ‘obesogenic environment’—an environment that promotes weight gain and discourages physical activity.

Modern life has fundamentally changed how we eat and move. Take the food environment, for example. We are surrounded by ultra-processed, calorie-dense foods—think chips, candy, sugary drinks, and fast food. These foods are not only cheap and widely available, but they are also marketed aggressively, especially to children. Research shows that diets high in ultra-processed foods are directly linked to weight gain and metabolic conditions like diabetes.

On top of this, our physical activity levels have plummeted. Many of us work sedentary jobs, rely on cars for transportation, and spend our leisure time on screens rather than on physical activity. These shifts have created a perfect storm for weight gain.

Cultural shifts have played a role. For instance, portion sizes in restaurants and packaged foods have increased dramatically over the past few decades. In the 50s, a soft drink was about 6 ounces; today, a ‘small’ is often 12 ounces or more. These larger portions encourage overconsumption, often of high-sugar and high-fat foods.

Another major shift is the normalization of eating out and consuming processed, ready-to-eat meals. These foods are often calorie-rich but nutrient-poor, contributing to weight gain without satisfying hunger.

The affordability of unhealthy foods is another piece of the puzzle. It’s often cheaper to buy a fast-food burger than a fresh salad, and sugary drinks are more accessible than bottled water. This economic reality disproportionately affects lower-income populations, who often face the highest rates of obesity and diabetes.

All of this has a dramatic effect on us, because from a biological perspective, humans are hardwired to seek out calorie-dense foods—a survival mechanism that helped our ancestors during times of scarcity. But in today’s world of abundance, this biological drive works against us.

Then we have other modern lifestyle factors, things like chronic stress and lack of sleep also contribute to obesity. When we’re stressed, our bodies release more cortisol, a hormone that promotes fat storage, especially around the abdomen. Studies also show that sleep deprivation disrupts hormones like leptin and ghrelin, which regulate hunger and fullness, leading to overeating.

But it doesn’t stop there. While diet, lifestyle, and cultural factors play significant roles in the growing rates or overweight and the obesity, there’s another, less visible contributor that deserves attention: obesogens. storage in ways many of us don’t even realize.

You might be wondering, what on earth are obesogens?

These are chemicals in our environment that interfere with the body’s natural hormones, promoting weight gain. These obesogens can be found in lots of everyday products—like plastics, food packaging, pesticides, and even some personal care items. For example, chemicals like bisphenol A, or BPA, mimic hormones like estrogen, altering how our bodies store and use energy. Obesogens can disrupt fat storage, increasing the size and number of fat cells. The can affect the hormones leptin and ghrelin, which tell us when we’re full or hungry, leading to overeating. Some obesogens can slow down the metabolism, making it harder for the body to burn energy efficiently, contributing to weight gain over time.

When you consider all this stuff, it begins to look like the odds are stacked against us, and in many ways they are. Essentially in our modern world, there are many systems-level issues, being overweight or obese is not simply about individual choices or willpower. In the modern world, the way our food systems and environments are designed often makes it difficult for people to make healthier choices, even when they want to. And frequently we’ve seen powers at play, such as big food and big pharma dominating commonly held narratives about food, about health – narratives that are not even true or based on strong evidence, as we’ve discussed in previous episodes. This is why combating obesity on a global scale requires changes not just at the individual level but also at the societal and policy levels.

Unfortunately though, at this point, making changes to improve our own health is largely left to us at an individual level, as the changes made at a societal and policy level are way too slow.

So, when it comes to developing prediabetes and type 2 diabetes, we often hear that being overweight contributes to our risk or causes these conditions, so let’s dive into the science behind the connection.

07:38

How exactly does being overweight or obese contribute to the development of pre or T2diabetes? The connection lies in how excess body fat affects the body’s ability to regulate blood sugar and insulin.

As we’ve spoken about in episode 26 and alluded to in many other episodes, at the heart of pre and T2diabetes is a condition called insulin resistance. Insulin is a hormone produced by the pancreas that helps cells absorb glucose, or sugar, from the bloodstream for energy. When you have insulin resistance, your cells don’t respond effectively to insulin, causing sugar to build up in your blood. While insulin is most commonly recognized as the hormone that helps regulate blood sugar levels, it also plays a key role in energy storage, fat storage. When blood sugar levels are high, insulin directs cells to store the excess energy, first as glycogen and then, when glycogen stores are full, as fat. When blood sugar levels are high, insulin levels are usually high and this promotes fat storage.

Excess body fat, especially visceral fat, is not inert—it’s metabolically active. It releases substances like free fatty acids and pro-inflammatory molecules that create a state of chronic low-grade inflammation in the body, systemic inflammation, something we delved into in episode 41. This inflammation damages tissues and disrupts insulin signaling, worsening insulin resistance. In other words, the more fat we carry—especially in and around our organs—the more likely our bodies are to exist in a state of persistent inflammation, setting the stage for pre or T2diabetes.

Obesity also alters the balance of key hormones that regulate blood sugar. For example, Leptin, the hormone that tells our brain that we’re full, becomes less effective in the presence of obesity, leading to overeating.

Another factor is the accumulation of ectopic fat, which refers to fat deposited in places it doesn’t belong, like the liver, pancreas, and muscles. When the liver is overwhelmed with fat, which is common in pre or t2diabetes, it can’t properly regulate glucose production, leading to higher blood sugar levels. Similarly, fat buildup in the pancreas can impair the beta cells that produce insulin. A fatty liver and fatty pancreas influences all sorts of metabolic processes in our bodies, and worsens insulin function and insulin resistance.

The gut microbiome plays a significant role in the relationship between obesity, prediabetes, and type 2 diabetes. Dysbiosis, or an imbalance in the composition and diversity of gut microbes, can contribute to metabolic dysfunction through several mechanisms, such as driving inflammation, disruption to the production of short chain fatty acids in our gut, dysregulated bile acid metabolism, along with influencing hormones involved in satiety, appetite, and insulin secretion. Yes, our gut bacteria play a role in many functions in our body, which is very fascinating.

Then there’s also epigenetic changes—those environmental factors that influence gene expression—those obesogens in the environment result in an increased likelihood that we may develop obesity and pre or T2diabetes.

There are quite a number of aspects at play here. Carrying excess weight can lead to pre and T2diabetes via a complex interplay of factors, ranging from inflammation and ectopic fat to hormonal disruptions and genetic predispositions to our gut microbiome and our environment.

12:12

So a question that often comes up is: does obesity cause diabetes?

While obesity is a major risk factor, it doesn’t directly ’cause’ the condition. Instead, it creates the conditions that significantly increase the likelihood of developing diabetes. Think of it as setting the stage for the body to struggle with blood sugar regulation. For many people, obesity acts as the tipping point, particularly when combined with other factors like genetics, lifestyle, or environmental influences.

We know that carrying excess weight—due to that systematic inflammation, the hormonal disruptions and the insulin resistance—places enormous stress on the body’s ability to regulate blood sugar, making pre and T2diabetes more likely. That’s why it’s often emphasized that we lose weight in order to reduce risk or in the treatment of pre and T2diabetes too.

It’s important to note thought, that the connection between obesity and diabetes isn’t absolute. Obesity often precedes diabetes because of the strain it places on the body, but not everyone with obesity develops diabetes. Similarly, not everyone with type 2 diabetes is obese. And that’s exactly what we’re going to explore further in just a moment.

14:18

Now that we’ve explored the connection between obesity and type 2 diabetes, it’s important to address some common myths and misconceptions.

Firstly, let’s address a common question: Do All Obese People Have Diabetes?

The short answer is no. Not everyone living with obesity develops pre or T2diabetes, and the reasons for this lie in the complex interplay between genetics, fat distribution, and lifestyle factors.

Let’s start with genetics. Some people are genetically predisposed to handle insulin resistance better than others. They may store excess fat in a way that doesn’t interfere as much with insulin signaling. Others might have genetic variations that protect their beta cells in the pancreas, allowing them to continue producing enough insulin despite insulin resistance.

Next, fat distribution plays a huge role. It’s not just about how much fat you carry but where it’s stored. People with a tendency to store fat subcutaneously—just under the skin, rather than around their internal organs—are less likely to develop metabolic issues. On the other hand, people with more visceral fat—the type stored around organs like the liver and pancreas—are at higher risk for insulin resistance and pre or T2diabetes.

Finally, lifestyle factors like diet, physical activity, stress, and sleep can either amplify or reduce the risk. An active person living with obesity who eats a quality balanced nutrition plan and manages stress well may not develop diabetes, while a sedentary person with poor eating habits and high stress may be at higher risk, even if they are at a lower weight.

16:10

Interestingly, it’s always assumed that if you have diabetes, you must be overweight, so here’s another common question: Can You Have Type 2 Diabetes Without Being Overweight or Obese?

The answer is yes, absolutely. Developing pre or T2diabetes is not exclusive to people who may be overweight or living with obesity. In fact, thin people can develop pre or T2diabetes, especially if they have other risk factors like visceral fat or ectopic fat accumulation, poor nutrition or lifestyle habits, or a strong genetic predisposition—all of these factors can potentially disrupt metabolic function, even if a person is not carrying excess weight.

For many reasons, which we’ve explored earlier in this episode, insulin resistance can still develop, regardless of body size.

17:25

So clearly, one thing we commonly hear is that weight loss is essential in treating pre or type 2 diabetes. A common question here is: Does weight loss cure diabetes—or even prediabetes?

Certainly, weight loss is a powerful tool for improving pre and t2diabetes. In prediabetes, modest weight loss—as little as 5-7% of your body weight—has been shown to significantly reduce the risk of progressing to T2diabetes by 58-71%.

The mechanism is similar to what we see in type 2 diabetes. Losing weight improves insulin sensitivity and reduces visceral fat, which lowers blood sugar levels and helps the body regulate insulin more effectively. The earlier you act—ideally during the prediabetes stage—the better the chances of restoring normal glucose metabolism and preventing progression.

This highlights an important point: With prediabetes, the window of opportunity for prevention is wide open, and modest weight loss combined with quality nutrition and other lifestyle changes can make a profound difference.

Now, when it comes to type 2 diabetes, weight loss is incredibly beneficial as well. Weight loss can help you achieve remission, but it’s not a guaranteed cure. Significant weight loss—around 20-35 pounds or 10-15 kilos—has been shown to reverse the condition in many cases, especially when it occurs early after diagnosis.

Again, this happens because weight loss improves insulin sensitivity and reduces fat stores in the liver and pancreas, which helps restore normal insulin function. Losing weight also reduces that systemic inflammation in your bodies cells, which has a big impact on how your metabolism functions overall.

While weight loss is a powerful tool, it’s not the only factor. Maintaining those lifestyle changes over time—through a combination of nutrition, activity, and stress management—is key to long-term success. It’s recognizing that being healthy is not just a goal but a way of living.

19:50

Let’s wrap up with some key takeaways from today’s episode.

First, there is a connection between obesity and diabetes. But carrying extra weight doesn’t automatically mean you’ll develop diabetes, and being thin doesn’t make you immune. It’s about much more than just the number on the scale—factors like visceral fat, inflammation, and insulin resistance all play a role.

Second, while weight loss can be a powerful tool for improving pre or T2diabetes—and even achieving remission—it’s not always a magic fix.

And finally, the most important thing to remember is this: improving your health is a journey. Small, sustainable changes to your nutrition, activity levels, and stress management can have a huge impact, no matter where you’re starting from. So wherever you are starting from today, what one additional thing could you do to improve your health? One small action step you could take? Small, consistent steps really do add up and make a big difference!

Please share this episode with someone who might also benefit from hearing it.

Take care until next week.

Dr Jedha, over and out.