Intermittent fasting entails going without food for an extended period of time (Famine) and then breaking the fast with a large meal (Feast).
This can be done in two methods:
1. 16:8 Rule– This type of IF is where you fast for 16 hours and eat a balanced diet for the next 8 hours
2. 5:2 Rule– This type of IF entails eating a balanced diet for 5 days and then restricting your calorie intake to 500 calories for the next two days
There are many known benefits of IF, some of which include:
· Normalization of insulin sensitivity
· Mitochondrial energy increase
· Increase HGH
· Lower inflammation
· Lower triglycerides
· Lower blood pressure.
· Shed unwanted fat
· Eliminate cravings
· Reduce oxidative stress
· Increase BDNF
· Increase longevity
Now the question remains, does IF work the same for men and for women??
The short answer is NO!! WHY?? Because men and women have differing needs all stemming from one’s core biology.
· Females have two X chromosomes whereas males have one X and one Y chromosome
· Males have a higher concentration of testosterone whereas women have a higher concentration of estrogen
· In terms of body composition, males typically have proportionately more muscle mass, more bone mass, and a lower percentage of body fat than women
· Prevalence of hypertension in women is lower compared with age-matched men as a result of higher estrogen concentration
· Coronary artery disease (CAD) risk is higher in men and their risk of dying from it at younger ages is higher
· Peripheral artery disease (PAD) is more prevalent in men than women at younger ages, but the incidence rises in women after menopause. Women, however, display more severe PAD compared with men at the time of clinical diagnosis and experience greater complications
· Migraines and other headache-related events are more dominant in females
· The incidence of stroke in men is approximately 33% higher when compared to females
· Obesity is more prevalent in women than in men globally
· The sex hormones in men and women control food intake and body weight. In general, male animals are larger and consume more food than females
Easiest explanation: WOMEN need MORE nutrients than MEN!! This is why IF doesn’t give the same results to women.
WHY, YOU ASK??
· Women need a consistent calorie intake each day to support their metabolic function
· Women release less glucagon (a hormone released by the liver to help raise blood sugar levels when they are low) compared to men
· Estrogen has a direct effect on fertility. So a calorie restriction, as seen in IF, can negatively affect the female reproductive system
· Women consume less protein and while fasting, they consume even less. This results in less amino acids being produced in the body, which are needed to activate estrogen receptors
· As these receptors are found more in women, this results in a cascade of side-effects which affects metabolic function all round
· Changing the estrogen balance changes metabolic function all over: cognition, moods, digestion, recovery, protein turnover, bone formation
· Research suggests that women have more kisspeptin than males, meaning greater sensitivity to changes in energy balance
· Research looking into livers of mice following IF indicates livers of male mice stop producing energy storage molecules, whereas livers of females make use of all available resources in an attempt to normalize the energy balance necessary to maintain the reproductive needs.7This means that, if needed, the woman’s body is more likely to tap into lean muscle mass as an energy source
For these reasons, it is clear that the biological and physiological make up of women directly affect their ability to adapt to a calorie restrictive eating style, such as IF.
THE BOTTOM LINE: WOMEN need to EAT CONSISTENTLY for BEST RESULTS!!!
#Check our next blog post for alternative options for women instead of IF.
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2. Boese AC, Kim SC, Yin KJ, Lee JP, Hamblin MH. Sex differences in vascular physiology and pathophysiology: estrogen and androgen signaling in health and disease. American Journal of Physiology-Heart and Circulatory Physiology. 2017 Sep 1;313(3):H524-45.
3. Dearden L, Bouret SG, Ozanne SE. Sex and gender differences in developmental programming of metabolism. Molecular metabolism.2018 Sep 1;15:8-19.
4. ISSA. International Sports Sciences Association Online. [Internet]. Online. ISSA. Available from: https://www.issaonline.com/blog/index.cfm/2018/this-hot-diet-trend-is-not-recommended-for women#:~:text=Overall%2C%20men%20tend%20to%20do,and%20eating%20styles%20discussed%20below.
5. Nutrafol. Why Intermittent Fasting is Different for Women. [Internet]. Online. Available from: https://nutrafol.com/blog/intermittent-fasting-men-women/
6. Well Effect. Intermittent Fasting – Different for Women and Men! [Internet]. Online. Available from: https://welleffect.com/intermittent-fasting-different-for-women-and-men/
7. FitPro. Intermittent Fasting Men vs. Women.[Internet]. Online. Available from: https://www.fitpro.com/blog/index.php/intermittent-fasting-men-vs-women/
8. Torre S (2018), Short-term fasting reveals amino acid metabolism as a major sex discriminating factor in the liver, Cell Metabolism, 28(2): 256-267.