February 1, 2023, Reviews
Recently I read Fast Like a Girl by Dr. Mindy Peltz and honestly, I was relieved. I never find fasting easy(who does?) but I persevere through sheer will power, knowing all the health benefits that come with it. Unlike my male friends, I find fasting much harder during certain times of the month, and now I know why, my hormones. This book is a brilliant manual for women who want to get away from fad diets to understanding how hormonal fluctuations impact appetite and mood. Learning how to modify your diet and lifestyle with the cycles of your hormones is extremely insightful and empowering.
One of the biggest lies told in the weight loss and fitness industries is that we should all be eating the same way. We have been conditioned to believe that calorie restriction leads to weight loss but this doesn’t always work long term. When you eat less your body eventually changes its set point, so you’re eating less and less to maintain. The underlying hormonal issues aren’t addressed. There is truth in thermodynamics- calories in, calories out, but the body is more complex than this. You end up eating less without longterm results, potentially causing nutritional deficiencies and not enjoying food see more about this here. Fasting is not about calorie restriction, it’s about time restriction. It’s not a fad diet, its a healing tool, and if you can make some adjustments you’ll be rewarded with much better health.
The latest Australian statistics indicate that 67% of adults are either overweight or obese, which is a risk factor for developing metabolic dysfunction aihw.gov.au. Poor metabolic health, also known as metabolic syndrome, and the resulting insulin resistance, is the root of many chronic diseases – high blood pressure, high cholesterol, high blood sugar. For women in particular the prevalence of chronic fatigue, polycystic ovarian syndrome and breast cancer has been steadily increasing over the last 20 years aihw.gov.au. Fasting has been shown to accelerate weight loss and reduce body fat, especially visceral fat around the organs, resulting in lowered blood pressure, cholesterol and insulin see study here.
On the podcast, The Huberman Lab, Andrew Huberman, discusses studies that show some striking data. When rats eat continuously they develop fatty liver and eventually liver disease. Conversely, rats that are fed within a restricted time frame reverse this liver condition and even develop healthier livers than the control group Huberman-fasting-youtube.
Something that really interests me is the way that fasting effects the body’s microbiome – the thousands of microbial species that live in and on us. Around 90% of our microbiome resides in the gastrointestinal tract and these microbes synthesise vitamins and minerals, modulate the immune system and make important neurotransmitters like serotonin. Unfortunately, many factors in our lifestyle and environment can negatively impact our microbiome – antibiotics, chemicals, processed food and even stress have been found to alter our good bacteria. Fasting has been shown to improve microbiome diversity, encourage equal distribution of microbes and regenerate stem cells that repair gut lining see gut-immune connection.
In Fast Like a Girl, Pelz cites multiple studies that show how longer fasts can kill precancerous cells and reboot the immune system, as long as it’s backed up with the correct diet once the fast is broken, “when you pair the right foods with fasting, miracles happen – especially for women”. Fasting for women and men is different. Although men, like women, are hormonally driven, they are not as sensitive to the hormonal spikes they undergo. For women to get the maximum benefits from fasting they must understand the ebbs and flows of their hormones.
Day 1-10 menstrual cycle: at the start of the cycle, the major hormones estrogen, progesterone and testosterone are at their lowest level. Estrogen slowly increases giving a sense of well-being and strength. Estrogen thrives when insulin is low, so this is the time to fast.
Day 11-15 menstrual cycle: during the ovulation phase estrogen and testosterone are the major players and this means you should find fasting a lot easier during this time.
Day 16-28 menstrual cycle: the second half of the cycle is when all hormones start to drop. Progesterone takes over as the predominant hormone which may make you feel less energetic, less strong, less mentally clear, and hungrier. This is the time to avoid fasting. Progesterone prefers higher glucose levels so fasting, that keeps glucose low, will be difficult to maintain and may exacerbate pms symptoms.
The body is constantly regenerating each and every cell. Old cells are replaced by new cells at different stages throughout the body. The way these cells repair and replace will be determined by a variety of mechanisms, one being autophagy, which literally means ‘self-eating’. This is a critical process the body uses to clean up cellular garbage and recycle damaged or diseased cells. A 2019 study analysed numerous longevity markers, including LC3A expression, the autophagy gene, finding that after fasting for 18 hours autophagy increased by 22%. In the absence of food, the body begins breaking down or ‘self-eating’ old or malfunctioning parts of the cell, viruses and toxins. Autophagy helps the liver convert fat soluble toxins into water soluble toxins which are then excreted through the bile and urine. This inbuilt housekeeping function has so many beneficial effects on the body, it is one of the main reasons fasting is such an incredible healing tool.
Fasting benefits include: