What Women Over 50 Should Know About Intermittent Fasting

For women over 50, weight loss can seem like a struggle for a variety of reasons—most of them related to a shift in hormonal balance. It’s no wonder that intermittent fasting has become so popular for women over 50 with its promise of amping up metabolism, reversing cellular damage (and its signs of aging), and improving mental clarity.  Let’s take a look at what happens to women’s hormones as we approach and enter menopause, and what the science says about whether intermittent fasting can help counter some of these imbalances.  Hormones and Women Over 50 During perimenopause and menopause, estrogen fluctuates and becomes unpredictable before falling to very low levels. This decline in estrogen comes with shifts in other hormones like cortisol, thyroid hormones, serotonin, and sex hormones. These hormonal shifts are what lead to some of the symptoms of menopause.  You may become less sensitive to insulin during menopause, leading to difficulties processing sugar and refined carbohydrates. This is known as insulin resistance, which might make you more susceptible to gaining weight around your midsection. Muscle mass may also diminish as fat increases, leading to less metabolically active tissue and difficulty maintaining a healthy weight.  RELATED: Thyroid Disease and Diet: Managing Thyroid Health With the Right Nutrients Cue intermittent fasting. With this unorthodox way of eating touting benefits for healthy aging, there’s no wonder that IF has been popular with perimenopausal and menopausal women. But does the research hold up?  What is intermittent fasting?  In short, intermittent fasting involves eating within a specific time window. The most popular version involves fitting all of your daily food consumption into an eight-hour window, followed by 16 hours of fasting. For example, you could eat between 10 a.m. and 6 p.m. every day and fast between 6 p.m. and 10 a.m. (including the hours you’re asleep).  There’s also the 5:2 diet in which you split your week into five days of eating whenever you want and two days where you seriously restrict your calories—500 for women, 600 for men.  While fasting may seem extreme for some, proponents of this dietary pattern claim that fasting causes your body to use stored fat as fuel.  RELATED: The Truth About Intermittent Fasting: Is It Good for Weight Loss and Overall Health? How does intermittent fasting work? What’s the evidence? The research on the health benefits of intermittent fasting is pretty interesting, with the latest findings adding a bit of inconsistency compared to previous results.  A study comparing two groups—a calorie-restriction-only group and a calorie-restricted and time-restricted eating group—followed subjects over the course of one year and found no effect on body weight, body fat, or metabolic risk factors. People who only ate from 8 a.m. to 4 p.m. didn’t lose significantly more weight than those who ate any time throughout the day. Any weight loss was attributed to overall caloric restriction rather than time-restricted eating regimens.  Other findings, however, have shown benefits for weight loss, insulin resistance, mental health outcomes, and brain cell activity. Let’s take a look at a few of those.  Weight loss Studies have found that intermittent fasting can help with fat loss by reducing body mass and improving metabolic health. They also show fasting can affect hormones, increasing production of beneficial ones like HGH (for muscle gain and fat loss). Still, these effects appear broadly comparable to standard daily calorie restriction.  In a study that compared the weight loss efficacy of alternate-day fasting (ADF) among pre- and post-menopausal women, body weight significantly decreased from baseline in both groups. This suggests that intermittent fasting may be effective in weight loss regardless of menopausal status.  Another study looked at time-restricted feeding and found similar results. Both pre- and post-menopausal women lost weight and showed metabolic improvements.  Insulin resistance Intermittent fasting’s effect on insulin sensitivity has been a hot topic in recent years. Researchers hypothesize that this is achieved by flipping a metabolic switch. Fasting leads to lower levels of glucose (i.e. blood sugar) and in response, the body uses fat instead of glucose as a source of energy.  Fasting can also lead to improvements in pancreatic B-cell function and the regulation of the circadian rhythm, which promotes better glucose tolerance. In a randomized controlled study of more than 100 overweight or obese women, six months of intermittent fasting reduced insulin levels by 29% and insulin resistance by 19%. Reductions in fasting insulin and insulin resistance were modest in both the intermittent fasting and continuous energy restriction groups, but greater in the intermittent fasting subjects. Another study on non-obese subjects also found that fasting decreased insulin levels and increased fat oxidation—the process that breaks down fat during energy restriction or exercise.  In one study, researchers looked at the effects of intermittent fasting versus continuous calorie restriction on HbA1c (a measure of average blood sugar levels over the past 3 months) in diabetics over the age of 50. They found that a two-day intermittent calorie restriction diet was comparable to a continuous calorie restriction diet for improvements in blood sugar control. Mental health changes  Menopause can cause anxiety, depression, fatigue, brain fog, mood swings, and psychological stress. Studies have found that fasting can improve depression and stress levels, and encourage overall positive psychological shifts. It is important to note that both of these studies were conducted in age ranges below 50 years old.  Brain fog Studies in animals have found that fasting can have positive effects on brain cells, by encouraging better stress responses and clearing out damaged cells in order to regenerate newer, healthier cells. Fasting has also been shown to increase BDNF expression in rats, a protein that serves as a sort of fertilizer or “miracle-grow” for the brain. There are no studies on how fasting affects the human brain yet, but one of the most common things people report while fasting is increased mental clarity.   Bottom Line: Intermittent Fasting for Women Over 50  While intermittent fasting shows promise, we don’t have solid evidence about the benefits or how fasting might affect