The female body has unique demands and more hormonal fluctuations than the male body, which affects the way the body reacts to dietary changes. As most of you know, I'm a big proponent of using nutrition and lifestyle changes to help increase the body's potential to burn fat, but there are limits. Unfortunately, ladies, the limits apply to us more than men. It may not seem fair, but we have this amazing ability to grow another human body within our bodies and we need to respect that. The body is very protective of this ability so our reproductive hormones are much more sensitive than the male reproductive hormones. This means that ladies need to be careful with changes in diet and lifestyle.
There is a lot of discussion about reducing carbohydrate intake to very low levels and using intermittent fasting to manage weight. These approaches can work, but I always tell people that women need to cautious with these approaches. This is why I don't go too low carbohydrate with myself or my clients or apply large windows of intermittent fasting. As I've stated many times, every body is different so it's important for women to pay attention to how their bodies respond to changes in diet and lifestyle. The good news is that our bodies send us clues much more quickly than the male body. Once it gets to the point of missed periods, it's gone too far.
This article does a great job on explaining the how the female hormone system is affected by intermittent fasting (going without meals for 18 or more hours per day). I advise that most people fast for 12 hours overnight to rest the digestive system and allow for cleaning of the GI tract. This also allows for the repair and recovery elsewhere in the body that should be occurring during sleep. If we go to bed on a full stomach, the body is busy digesting food and has less energy to restore. Some people fast for longer periods of time to help improve the ability to burn fat and reduce overall body fat. Men can do this more easily than women and tend to have a better response. Women should pay attention to how they feel and keep the fasting window closer to 12 hours, if they receive signals that they body is not adjusting to the change. Signals can include:
- Reduced energy levels
- Disrupted sleep
- Inability to regulate body temperature
- Thinning, dry or brittle hair, skin or nails
- Increases in illness or injury
- Loss of desire for things that used to provide enjoyment
- Inability to deal with stress,
Female athletes also need to careful with fasted workouts. Fasted workouts stress the body and spike cortisol. I advise these workouts to be no longer than 30-60 minutes, depending on health and fitness status.
Carbohydrate intake needs to also be considered, which is why I incorporate a controlled carbohydrate plan that includes a high level of non-starchy vegetables. Some women can do fine on only these, but others need to add more starchy vegetables and fruit. Female endurance athletes have higher needs for fruit and starchy vegetables, but, again, it will vary by individual and it's important to consider carbohydrate timing. It's also very important that healthy fats are increased if carbohydrate intake is reduced. The overall caloric intake should not be too low and healthy fats will minimize that risk.
My main message is health first. Performance and body composition will follow. Women need to appreciate all the amazing things that our bodies can do and respect our differences from men. Listen to your body, it will tell you what it needs.