Weight loss is something most people struggle with. The number of people who are overweight and obese has climbed in the past few decades and it’s not completely clear why. Experts have explored a variety of possibilities including:
· Supersized portions
· Soft drinks, processed foods, and sugar
· Lack of physical activity
· Obesogens in the environment
· Changes in sleep patterns
It’s possible that all these factors play a role. What’s also disturbing is the rise in metabolic issues, like insulin resistance and type 2 diabetes, an epidemic now described as “diabesity.” Unfortunately, reversing the diabesity epidemic is a challenge, made more challenging by the fact that some people have it and don’t know it. It’s a frustrating problem that shows no sign of abating. However, a new study shows that even modest weight loss can have a significant impact on health. How much do you need to lose? Based on this study, shedding as little as 5% of your body weight can improve your metabolic health.
What the Study Showed
In a study published in the journal Cell Metabolism, researchers conducted a randomized controlled trial comparing the impact of losing a small amount of weight, 5.1% of total body weight, versus losing a more substantial weight loss, around 16.4% of total body weight. What they found was participants who lost only 5% of total body weight experienced a significant improvement in insulin sensitivity, the way in which their body handles insulin. They also showed improvements in the function of beta-cells, the cells in the pancreas that produce insulin.
The participants in the study experienced further improvements in metabolic health with weight loss beyond 5%, such as greater fat loss, a reduction in liver fat, improvements in lipids, and a reduction in oxidative stress. The good news is the study shows that losing even a modest amount of weight (5%) is beneficial for metabolic health. So, you don’t have to experience massive weight loss to improve how your body functions from a metabolic standpoint.
Improving Insulin Sensitivity
Why is this important? Insulin resistance and metabolic syndrome is a leading driver of chronic health problems like type 2 diabetes and heart disease. Plus, research links insulin resistance and higher insulin levels with a greater risk of cancer. Insulin is a growth factor that drives the growth of normal tissue and cells as well as abnormal, precancerous ones.
Anything we can do to improve insulin sensitivity is favorable for health and longevity. That’s why it’s encouraging that such a modest weight can cause measurable improvements in metabolic health. Most people feel like they have to lose a large amount of weight to improve their health. Encouragingly, even 5% may offer measurable benefits. What’s interesting is researchers believe that the first 5% of weight loss has the MOST health benefits. So, if you’re 150 pounds, losing just 7.5 pounds can boost how your cells respond to insulin.
Once you crack the first 5 pounds and insulin sensitivity improves, further weight loss may be easier. When your cells are resistant to insulin you have higher levels of insulin circulating in your blood and it makes it harder to lose weight. Insulin turns on a hormone called lipoprotein lipase that encourages fat cells to take up and store fat and dials back hormones that break down fat. High levels of insulin make it difficult to lose body fat even when you’re exercising and watching your calorie intake.
If you can lose just 5% of your body weight, it helps break the hold that insulin resistance has on your body. Plus, as insulin sensitivity improves, it makes it easier to lose more weight. Poor insulin sensitivity is often a sticking point for weight loss in people who are overweight or obese and sometimes even in people who are lean. As many as 10% of lean people have some degree of insulin resistance and don’t know it.
What happens if you lose more weight? Studies show that losing more, 10% of total body weight, can lower blood pressure and improve blood lipids. So, you can expect further benefits beyond 5% weight loss.
Fat Loss vs. Muscle Loss
One problem with looking at weight loss is you don’t know the type of tissue you lost. Shedding body fat is beneficial but you can’t choose the type of tissue you lose. The best way to shift weight loss toward body fat and away from muscle loss is to exercise. Studies show that resistance training helps preserve lean muscle tissue when you’re on a lower calorie diet. High-intensity interval training helps burn fat as well. It’s a good combination for losing body fat and improving insulin sensitivity as well.
How do you know if you’re insulin resistant? Health care professionals base the diagnosis of insulin resistance on these criteria:
· Fasting triglyceride level of 150 mg/dL or higher
· Waist size of more than 40 inches in men or more than 35 inches in women
· High-density lipoprotein cholesterol (HDL-C) level of less than 40 mg/dL in men or less than 50 mg/dL in women
· Blood pressure level of 130/85 mm Hg or higher
· Fasting glucose level of 100 mg/dL or higher
To be classified as insulin resistant, you would need to meet 3 or more these criteria.
Unfortunately, insulin resistance becomes more common with age, especially in women after menopause and those who are inactive. An active lifestyle and avoiding weight gain helps preserve insulin sensitivity. However, some people are genetically predisposed, which is why you sometimes see insulin resistance in thin people.
As you might expect, diet is an important factor in preserving insulin sensitivity. Many experts believe the Western diet rich in processed foods and sugar are major contributors to the problem of insulin resistance and the diabesity epidemic, whereas studies show eating a Mediterranean-style diet is beneficial. As a bonus, the Mediterranean diet is linked with lower mortality from all causes. So, enjoy the variety that a Mediterranean-based, whole food diet offers.
The Bottom Line
You don’t have to lose a large amount of weight to have a big impact on your health. Losing as little as 5% of your body weight can improve insulin sensitivity and metabolic health. For most people, that’s manageable.
Endocr Relat Cancer February 1, 2013 20 R1-R17.
Curr Diab Rep. 2013 Apr; 13(2): 213–222.doi: 10.1007/s11892-012-0356-6.
Medscape Family Medicine. “Insulin Sensitivity Improved With Mediterranean-Style Diet”