Weight gain in middle age is challenging and very common.
I see many women over the age of 40 that are frustrated with their weight. They are eating healthy and exercising, but the extra weight just won’t come off! Some women even decide to “clean up” their diet and hit the gym even harder but still…no change. Weight gain has been said to be nothing more than your body’s chemical reaction to foods. It’s not that you’re eating too many calories or not exercising enough. It comes down to 2 things: hormones and inflammation.
As women go through their middle years, their body composition changes in proportion to fat.
The proportion of fat to body weight tends to increase (more than men), and fat storage begins favoring the upper body over the hips and thighs. In other words, your waistline starts to grow in inches as visceral fat (the fat that wraps around your abdominal organs) pushing out against the abdominal wall.
What we have learned since the mid-1990’s, is that the fat cell is an endocrine organ, secreting hormones and other molecules that have far-reaching effects on other tissues. There are a host of chemicals that link visceral fat to a wide variety of diseases.
While subcutaneous fat produces a higher proportion of beneficial chemicals, visceral fat produces chemicals that are far more harmful. Visceral fat makes more of the proteins called cytokines, which triggers low lying inflammation and is a risk factor for heart disease and other chronic conditions. It also produces a precursor to angiotensin, a protein that causes high blood pressure.
We know that there is a hormonal mechanism that perpetuates middle age weight gain (obesity) through eating high glycemic foods. Foods that have a high glycemic index pack alot of sugar into a small package. High glycemic foods cause a fast rise in blood sugar resulting in insulin release. Highly processed refined carbohydrates are absorbed quickly, increasing insulin levels that can result in rebound hypoglycemia and insulin resistance. These mechanisms increase insulin sensitivity in adipose tissue but create insulin resistance in muscle and brain. Over time, fat accumulates viscerally while less is taken up in the muscle. Your body continues to make more and more insulin which leads to metabolic dysfunction, inflammation, weight gain, fatty liver and plaque development.
Other research by Mengeste and colleagues describes the characteristics of muscle between obese and lean people.
The obese muscle changes its composition to a muscle fiber (type 2) that is less able to utilize sugar for energy. This is because the number and function of mitochondria decline. These muscle fibers fatigue more easily than the dominant type 1 found in lean people. This is where exercise is so important but initially will not result in quick weight loss because the muscles are less able to absorb and burn energy.
What Does This Mean and What Can We Do?
All calories are not the same. Carbohydrates that are refined and have less fiber get absorbed very quickly and trigger hormones that allow the accumulation of fat. This changes muscle fibers and its function, making weight loss and exercise more challenging. So eating less and exercising more just doesn’t work…especially in middle age. High quality food is key.
So what can we do after age 40 (or even after age 35!)
- Eat more multicolored fiber-rich whole foods
- Eat more fiber and protein with a carbohydrate to slow absorption
- Drink a glass of water with 1 tsp of psyllium husks (or any soluble fiber) before meals to help reduce the glycemic index of a meal. Here is a patient handout on glycemic index/load.
- Do not use artificial sweeteners. They can actually exacerbate obesity
- Try to sustain good nutritional and exercise habits over time to increase type 1 muscle fibers. These muscle fibers have more mitochondria to help burn sugar and fat while increasing muscle endurance.
- Ludwig DS, Aronne LJ, Astrup A, et al. The carbohydrate-insulin model: a physiological perspective on the obesity pandemic. Am J Clin Nutr. 2021 Sep 13. doi: 10.1093/ajcn/nqab270. Online ahead of print. https://academic.oup.com/ajcn/advance-article/doi/10.1093/ajcn/nqab270/6369073
- Mengeste AM, Rustan AC, Lund J. Skeletal muscle energy metabolism in obesity. Obesity. 2021;29(10):1582-1595 https://onlinelibrary.wiley.com/doi/10.1002/oby.23227
- Jovanovski E, Khayyat R, Zurbau A, et al. Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of Randomized Controlled Trials. Diabetes Care. 2019;42(5):755-766. https://care.diabetesjournals.org/content/42/5/755.long