Fasting, whether for religious, cultural, or health reasons, has gained immense popularity in recent years. From intermittent fasting to extended fasts, many turn to it for weight management, improved metabolism, and better focus. However, emerging evidence suggests that fasting affects men and women differently both physiologically and hormonally; therefore, the approach must include awareness and necessary balance.
During a recent episode of her health podcast Take 20, Samantha Ruth Prabhu explored the impact of fasting on men and women, in conversation with holistic wellness and chronic disease reversal expert Dr Mitrabasu Chhillar.
“As far as fasting is concerned, I will say that women are from Venus and men are from Mars. We are dealing with totally different physiologies altogether,” said Samantha, to which the expert replied: “If someone has to go on a fast, I will never suggest that they fast during the luteal phase, because your energy requirement is more during that time.”
To better understand the physiological and hormonal differences between men and women and how these differences impact fasting for each, we reached out to Fiona Sampat, Clinical Dietitian at Kokilaben Dhirubhai Ambani Hospital, Mumbai.
How fasting affects men
According to Sampat, men generally respond more favorably to fasting in terms of metabolic benefits. “Studies indicate that intermittent fasting can enhance insulin sensitivity, promote fat loss, and support muscle retention in men. However, excessive fasting or skipping essential nutrients can lead to fatigue, reduced muscle mass, and nutrient deficiencies over time,” she shared.
The dietitian explained that intermittent fasting can alter the level and frequency of hormone secretion (such as insulin, thyroid hormones, and glucocorticoids) and may impact testosterone levels over time if it involves consistent under-eating or high stress. Men who engage in intense physical training should ensure adequate calorie and protein intake during eating windows to maintain muscle health.
When done mindfully, fasting can still improve digestion, energy levels, and mental clarity for women (Source: Freepik)
Adequate amounts of lean protein, complex carbohydrates, and healthy fats should be included in the diet to support sustained energy and muscle mass improvement.
How fasting affects women
For women, fasting has a more complex impact due to hormonal fluctuations. “The female body is highly sensitive to energy availability because it directly influences reproductive hormones like estrogen and progesterone. Extended fasting or severe calorie restriction can trigger irregular menstrual cycles, fertility issues, mood swings, or thyroid imbalances,” said Sampat, adding that some women may even experience increased stress hormone (cortisol) levels, which counteract fasting benefits.
That said, when done mindfully, fasting can still improve digestion, energy levels, and mental clarity for women. Quoting a study, Sampat detailed that women benefit more from shorter fasting windows (12–14 hours) and from eating earlier in the day, rather than skipping breakfast or fasting 16–18 hours.
What both should keep in mind
Whether you are a man or a woman, certain rules apply to both when it comes to fasting. Sampat listed down a few:
Personalisation is key: There is no one-size-fits-all fasting plan. Age, activity level, and health conditions must guide the approach.
Hydration matters: Fasting can lead to dehydration and electrolyte imbalance. Drinking enough water and incorporating mineral-rich fluids, such as coconut water or buttermilk, can help.
Nutrition quality over quantity: Breaking the fast with processed foods defeats the purpose. Opt for balanced meals that include complex carbohydrates, lean protein, and healthy fats. Breaks from fasting must include high-quality protein, healthy fats, fibre-rich carbs, and micronutrients. A “junk-carbs rebound” undermines benefits.
Avoid extremes: Long-term, restrictive fasting without medical guidance can lead to nutrient deficiencies and hormonal imbalances in both sexes. Extended daily fasting beyond one’s tolerance, chronic caloric deprivation, or prolonged fasts without refeeding planning can lead to nutrient deficiencies, hormonal disruption (including thyroid and sex hormones), low bone density, and immune compromise.
Listen to your body: If you feel dizzy, weak, or unusually irritable, it’s a signal to pause and reassess your fasting routine.
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
Samantha on why fasting is different for men and women (Source: Instagram/@samantharuthprabhuoffl) 
When done mindfully, fasting can still improve digestion, energy levels, and mental clarity for women (Source: Freepik)
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