Low carbohydrate diets can be very problematic and yet, it continues to be pushed hard in perimenopausal and menopausal women. How and what to eat will potentially be an ongoing debate, it’s important to take the time and figure out what your body needs and try to find balance and moderation in all areas.
Low carb gets encouraged for weight management, body composition changes, metabolic health, and sports performance. Some might see changes on the scale or in their pant size temporarily when embarking on a low carb diet. These results are related to improved glucose regulation and often plateau quickly.
Carbohydrates are the primary energy source for your body. Fats and proteins are secondary fuel sources. The message of limiting carbs to force your body to burn fat is somewhat true but not completely as carbs are needed to actually burn fat for energy. It’s a much more nuanced process than just avoiding carbohydrates.
More concerning is how your body has mechanisms in place that when a low calorie or low carb situation is detected, it shifts into conservation mode: slowing metabolism, decreasing thyroid function, lowering energy, storing more fat, and reducing your ability to build lean muscle.
When you don’t eat enough and don’t eat sufficient carbs, your body raises cortisol and reduces T3 production – you’re most active thyroid hormone. In women, elevated cortisol causes a shift in the body to prioritize fat storing, specifically around the abdomen. It’s an evolutionary trait that served us well when faced with the feast or famine lifestyle, less so in our current world with endless daily stressors of all kinds.
Elevated cortisol disrupts sleep. With poor or inadequate sleep, we see further cortisol imbalance. I see this a lot in my practice, difficulty falling asleep and staying asleep, or the classic waking up at 2 am and unable to fall back to sleep all because of insufficient calories and/or carbohydrates.
Other consequences of low carb diets are micronutrient deficiencies, brain fog, irritability, depression, hormonal imbalances, infertility, decreased thyroid function, and increased risk of osteoporosis (even in men).
When working out, carbohydrates are the primary fuel for your muscles. Your muscles and liver keep some of this fuel stored as glycogen for moments when available sugars for continued output are low, but these stores are limited. If you are not eating carbs, your body will run out of glycogen quickly. It will shift towards burning protein and fats but again, these are slow and less efficient sources of energy. In response, your body starts to decrease output – less energy, muscle fatigue, less power, higher cortisol, poor balance, brain fog. From a performance perspective, it’s all the things you don’t want to experience in your training or races.
Current research has shown low carb diets blocking muscle growth (hypertrophy) and anaerobic performance (sprinting). Low carb is more prevalent in power and strength sports, but it may be dampening outcomes in those trying to build muscle and high-intensity athletes. <<link article>>.
Undereating is a major problem for women and it’s not hard to understand why. We’ve been bombarded for decades with the story that if we eat less, we’ll lose weight and feel better. It’s not true. Undereating not only causes negative short-term consequences, if it goes on long enough many of the damaging hormone, metabolic and bone loss consequences are irreversible.
Perimenopause and menopause are already fraught with cortisol and sex hormone imbalances. Low carb and low-calorie diets compound these imbalances. The path to having great energy, clear thinking, positive and stable moods, and a lean body is fueling appropriately!
Estrogen influences your body’s ability to access glycogen stores (your stored fuel). Depending upon where you are in your menstrual cycle or if you are menopausal, you may be more reliant on dietary carbohydrates to fuel your muscles (and brain).
With consistently low estrogen in menopause, you are primed to use fats as fuel. Women are more adept at burning fats for fuel then men, but the problem is you need carbohydrates to kickstart the fat burning and replace any used glycogen reserves.
Low carb diets reduce the activity of kisspeptin; a neuropeptide that influences your appetite, body composition, and sex hormones. When kisspeptin decreases in response to inadequate carbohydrates, it increases your appetite, delays your sense of feeling full and encourages the storing of body fat.
Undereating, where you are not taking in enough calories to meet the needs of your body is problematic on all fronts. Not eating enough carbohydrates can contribute to undereating and has its own list of troublesome consequences that go well beyond poor performance.
Instead of a low carb diet, I suggest a “mindful carb” diet. Where you get your carbohydrates from and what you pair it with makes a massive difference in your metabolism, metabolic health, body composition, energy, cognitive function, and physical performance.
Sourcing your carbohydrates from vegetables, fruits then grains is preferably over refined flours found in breads, pastas, and baked goods. Pair your carbohydrate with a protein and/or a fat as this helps stabilize your blood sugars.
All your workouts should be fueled by carbohydrates and some protein – meaning, don’t workout fasted. As to how much and what ratio of each depends on the type and duration of your workout. Follow your workout with protein and quality carbohydrates to access a recovery state as quickly and effectively as possible. The protein post workout is essential to building lean muscle. Delaying your recovery further disrupts your cortisol and decreases any potential gains.
Food is fuel. Your need fuel to function, feel good, think clearly, and crush your goals. Mindfulness and moderation are great tools to nourishing yourself appropriately. Perimenopause and postmenopause are challenging enough. You don’t need to add in suffering through a highly restrictive diet that sets you up for further hormone issues and stress.