You’re probably aware that there’s a link between type 2 diabetes and body weight. In fact, obesity accounts for 80 to 85 % of the risk of developing this chronic health condition. So closely are they related that experts have coined the term “diabesity” to describe the strong association between the two conditions.
The link between body weight and type 2 diabetes can be explained by the fact that obesity is linked to insulin resistance. Insulin resistance is a term you’re probably already familiar with. It’s where insulin becomes less effective at getting glucose into cells. To compensate, the pancreas is forced to produce more insulin to get the job done. The constant demand to make more insulin places stress on the pancreas and eventually the insulin-producing cells, called islet cells, can burn out and not be able to keep up with the demand.
Therefore, one of the most important things we can do to lower our risk of developing type 2 diabetes is to stay a healthy body weight. Yet, often, our body weight fluctuates over time. There may be periods when we weigh a bit too much and times when our body weight is ideal. How do body weight changes influence the risk of developing type 2 diabetes?
Why We Need to Prevent Childhood Obesity
It starts early. The risk of developing type 2 diabetes may be influenced by how much you weighed as a child. A long-term study that looked at more than 62,000 Danish men found those who were overweight as children were at higher risk of developing type 2 diabetes as adults. In this study, timing was a factor. Guys who were overweight during childhood and lost the weight between the ages of 7 and 13 years of age and maintained it into adulthood had no greater risk of developing type 2 diabetes than those who weren’t overweight as kids. Good news!
However, those who were overweight and didn’t lose the weight prior to adulthood were at significantly higher risk of developing type 2 diabetes. This study certainly makes a strong case for keeping kids active early in life to help keep their weight down. Childhood obesity can come back to haunt you later.
How Does Excess Body Fat Cause Insulin Resistance?
The reason insulin resistance is worsened by carrying extra body weight isn’t completely clear. One factor seems to be inflammation. We know that fat, particularly deeper tummy fat called visceral fat, produces inflammatory chemicals called cytokines. These inflammatory chemicals fuel insulin resistance.
How do you know if you’re at risk? Carrying excess fat around the waist is a marker for insulin resistance, even in people who don’t fall into the obese category based on body mass index or BMI. Normal weight obesity is a growing problem and is characterized by having a body fat percentage that signifies obesity while still having a normal BMI. Remember, BMI doesn’t differentiate between fat and muscle tissue and that’s why it’s not an ideal marker.
How do you know if you are “obese” based on body size and are at high risk of insulin resistance? Measure your waistline. If your waist measurement is more than half your height, that’s a red flag. It pays to keep tabs on your waist size, just as you monitor other health parameters, like blood pressure, blood sugar, and lipids.
The Good News about Body Weight and Type 2 Diabetes Risk
Research shows being overweight or obese as an adult boosts the risk of developing type 2 diabetes by 1.5 to 5 times. Plus, people who are more severely obese have a higher risk than those who are moderately overweight or mildly obese. But, losing excess body weight can have a big impact on overall risk. That’s because losing weight reduces the number of fat cells actively producing inflammatory factors, which in turn improves how insulin functions.
How you go about losing weight also has an impact. When you’re physically active, cells take up glucose without the need for insulin. We know that exercise of all types improves insulin sensitivity even after a workout is over. In fact, studies show a single exercise session enhances insulin sensitivity by up to 40%. If you’re at high risk of diabetes, you want the extra “push” that exercise offers.
What’s more, exercise improves insulin sensitivity even in people who don’t lose weight as a result of exercise. So, exercise has an independent benefit on insulin sensitivity, irrespective of whether you lose weight as a result. However, you have to exercise regularly to get the benefits, as the impact on insulin sensitivity isn’t permanent. But it’s even better if you exercise and exercise leads to weight loss. That will substantially reduce your risk of developing type 2 diabetes.
You might think that aerobic exercise is the best type of workout for improving insulin sensitivity and lowering type 2 diabetes risk. While you should do exercise that gets your heart rate up, resistance training is important as well. Resistance training builds muscle and muscle acts as a reservoir to remove glucose from the bloodstream. In one study involving post-menopausal women, those who did both aerobic and resistance training enjoyed greater improvements in insulin sensitivity compared to those who did aerobic exercise alone. Plus, they lost more belly fat.
Why It’s Important to Take Control!
Type 2 diabetes and even pre-diabetes, where your blood sugars are modestly elevated, is associated with a higher risk of cardiovascular disease and premature death. One study found that every 1% increase in hemoglobin A1C, a measure of longer-term glucose control, was linked with a 20% higher risk of developing cardiovascular disease. If you go on to develop type 2 diabetes, it can damage blood vessels throughout your body and lead to kidney disease and loss of vision due to retinopathy. Plus, uncontrolled blood glucose damages nerves and can lead to a painful condition called neuropathy. As you can see type 2 diabetes has far-reaching effects on the human body.
The Bottom Line
Although you can develop type 2 diabetes at any weight, being overweight or obese increases the odds. One thing we can do to lower our risk is to maintain healthy body weight through exercise and by eating an unprocessed diet. Having more muscle helps too, so don’t underestimate the importance of resistance training as well.
Diabetes.co.uk. “Diabetes and Obesity”
Family Practice News. May 15, 2018. “T2DM Risk May Hinge on Childhood Weight”
Diabetes Spectrum 2003 Oct; 16(4): 261-266.
Diabetes Care 2003 Mar; 26(3): 944-945.
Diabetes Self-Management. “Increasing Insulin Sensitivity”