Midlife can often feel like a perplexing transition, especially for many women who experience unwelcome changes in their bodies. A frequent complaint is weight gain that seems unexplainable: “The things that worked before just don’t work anymore.” This is a common sentiment among my midlife clients, who visit healthcare providers hoping for answers. However, tests for thyroid function, blood sugar, and insulin levels often return with normal results, leaving them feeling frustrated and unheard. The conclusion? “Great news! You’re just getting older.” Yet, this narrative overlooks a significant aspect of midlife health, which is that our insulin does not function as efficiently as it once did. Understanding this phenomenon and implementing effective strategies can empower you to reclaim your health.

As estrogen production in the ovary decreases with less frequent or absent menstrual cycles, bone density and muscle mass also decrease due to changes in circulating estrogen and estrogen receptors on muscle cells and the mitochondria (“batteries” that supply energy for the cells). Muscles are the greatest utilizer of blood glucose in the body, second only to the brain. When muscle mass and power decline, blood glucose utilization also declines making it more difficult for insulin to manage circulating blood glucose. As a result, more glucose is stored as fat. There are other players in the hormonal pathways that manage carbohydrates that are also impacted by perimenopausal and menopausal change, however, the action of the muscles is a very significant contributor and is one that we can specifically address with exercise. Unlike pre-diabetes or metabolic syndrome, which require specific criteria for diagnosis, many women experience metabolic shifts without any abnormalities appreciated on laboratory testing. 

Your Body on Carbs

Carbohydrates play a significant role in how your body manages energy. When consumed, they are broken down into glucose, which enters the bloodstream. Insulin, produced by the pancreas, helps facilitate the uptake of glucose into the body’s cells, where it can be used for energy. However, with the hormonal changes of mid-life, the ability of insulin to move glucose out of circulation into the cells decreases, and glucose may remain unutilized resulting in greater storage of fat that can contribute to unwanted weight gain.

Although the changing biochemical pathways responsive to the hormones of the menstrual cycle are contributing to the loss of muscle mass, strength, and power, other pathways exist that can effectively stimulate the muscles to maintain (and even increase) skeletal muscle function independent of the reproductive hormonal pathways.  This is where exercise comes in! 

Strategies to Combat Insulin Resistance

Fortunately, several strategies can mitigate the effects of insulin resistance and promote healthier weight management and maintenance of muscle mass, strength, and power. 

1. Resistance Training

One of the most effective ways to enhance glucose utilization in muscles is through resistance training. Engaging in weight training stimulates muscular growth and adaptation mechanically and promotes glucose utilization by activating the GLUT4  glucose transporter pathway, which is less dependent on the reproductive hormonal pathways.  

For those who may be new to exercise, starting with simple activities like walking for 30 minutes, 3-5 times per week can be beneficial. As you progress, level up your training with weights, resistance bands, or even bodyweight exercises like push-ups  2-3 times a week. If you’re unfamiliar with weight training, seeking guidance from a personal trainer can help you build the necessary skills and confidence.

2. Nutrition Matters

The type of carbohydrates consumed can significantly impact blood sugar levels. The “Glycemic Index” (GI) is a measure of how a particular food impacts insulin levels. Foods in the “high” GI category spike insulin levels more dramatically than “low” GI foods which cause a slower, steadier rise in blood sugar which allows greater opportunity for the cells to use glucose for energy, rather than storing it as fat.

Charts that categorize various foods by their glycemic index score can be helpful in gaining awareness of the impact that the foods you consume have on insulin secretion. Many healthcare providers also utilize the continuous glucose monitor (CGM) to help understand how your body responds to specific foods. These tools can help you and your trainer design a nutrition plan that optimizes carbohydrate management specific to your physiology. 

Nutrient timing is another strategy for efficiently managing carbohydrate intake. Focusing the bulk of your carbohydrate intake at the beginning of the day allows a greater opportunity for using blood glucose as fuel during the increased activity of the day as compared to consuming large amounts of carbohydrates closer to bedtime.   Additionally, timing your carbohydrate intake within an hour before and an hour after exercise, can help optimize energy utilization and recovery by providing fuel when the body needs it most.

3. Beware of Paradoxical Insulin Resistance

Occasionally an athletic female with a rigorous training and nutrition regimen will show evidence of clinically apparent insulin resistance on blood testing. This phenomenon is sometimes seen in athletes who are in an energy imbalance where they are not consuming enough total energy and carbohydrates to fuel their physical activity and normal bodily functions. When this imbalance is persistent and prolonged, the body tries to compensate for this carbohydrate insufficiency by liberating glucose into the bloodstream in sometimes erratic patterns detected on a CGM, which can lead to abnormal insulin and glucose levels in the blood. Healthcare providers and trainers often misinterpret this data and start restricting carbohydrates further, which worsens the problem. It is thus critically important to consider the athlete’s complete training and nutrition history in helping her to manage both relative and clinically apparent insulin resistance. 

Key Takeaways for Midlife Health

Combatting relative insulin resistance during midlife involves a multifaceted approach. Here are the essential points to keep in mind:

• Start moving: Engage in physical activities that you enjoy and add resistance training 2-3 times per week as a goal.  
• Focus on nutrition: Be mindful of the glycemic index score of the foods you consume to control blood sugar levels effectively and ensure optimum energy balance. 
• Be patient: Progress takes time, and every positive change contributes to your health.

Tackling relative insulin resistance during midlife requires a multifaceted approach involving physical activity, nutrition, and effective recovery. By committing to regular resistance training, making mindful nutritional choices, and ensuring energy balance, you can take meaningful steps toward optimizing your health during this transitional phase. Remember, progress takes time and patience. For personalized guidance, consult with Dr. Carla DiGirolamo who can provide tailored strategies to support your journey toward optimal health.