Men vs Women in Nutrition

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You have heard it before: Men are from Mars. Women are from Venus.  The popular relationship book tried to explain the reasons men and women often appear to communicate, behave and express emotion differently. And now, the science also shows that men and women are different when it comes to nutrition. 

The data gap

Medicine sees our reproductive organs and hormones as the greatest source of difference between men and women. Yet, despite fundamental physiological differences, for centuries we assumed (and sold the idea) that women and men work the same way and can be fixed the same way. The reality is we actually don’t have much science focusing on women. The fluctuation of multiple hormones and the different hormonal phases women go through is seen as a “challenge” to a researcher. Women are understudied, underdiagnosed, and undertreated. Fortunately, in recent years there has been a big drive to improve the sex/gender gap in research, we know more know about how women work than ever before…. however, there is still a long way to go. 

What we know. The power of hormones

It’s no secret women have menstrual cycles. During this cycle the main female hormones oestrogen and progesterone go from low levels (luteal phase) to elevated levels (follicular phase) before dropping again; this drop is what causes a woman’s menstrual cycle. Other than menstruation these reproductive hormones impact many systems of the body from fluid regulation to metabolism to maintaining core body temperature and how we sleep! At the menopause there is a dramatic drop in all female reproductive hormones and post menopause these levels remain low.

Men on the other hand, do not have the same peaks and troughs of hormones as women, nor do they have the same hormones.  Testosterone is the main sex hormone in men. Most testosterone is made in the testicles. Small amounts are also made in the adrenal gland (in the kidney). Testosterone plays an important role in libido, muscle mass, fat distribution, bone mass and the production of sperm. A small amount of circulating testosterone in men is converted into oestradiol, a form of oestrogen. As men age, they often make less testosterone and consequently oestrogen however this decrease is often very gradual.  Women have testosterone to, however in much smaller levels than men.

Nutritional requirements Men vs women.

Energy intake

Pound for pound, women have the same energy requirement as men however new research shows that many active women overwhelmingly miss that mark and don’t eat enough. From a total energy standpoint, the paper explained that professional male and female athletes both need to consume 40 – 60 calories per kilogram of fat free mass to meet their energy needs. A new study found that 88 percent of women in the fell short of eating enough and had low energy availability. Although this study is on professional football plays, this situation is certainly not confined to sport. In my clinical practice I see this every single day. This is also backed by research which shows that 45% of female recreational exercisers fall into the sub clinical classification of low energy availability. Low energy availability is when your body goes into an energy saving mode due to not receiving enough calories to cover all the calories being burnt. Studies show that a female body can go into “energy save” mode after only four days of not meeting her essential calorie intake (resting metabolic rate). You can liken what happens in low energy availability in your body to your phone. When the energy save mode is activate on your on your smart phone, the screen light is dimmed, the background apps get turned off, and the device slows down. Essentially the same happens with the body. Bodily functions that are not immediately life-sustaining (such as menstruation and the ability to conceive) get downregulated and shut down until more energy becomes available to the body. The impact of the downregulation of hormones means that you are more likely to having weaker bones thus increasing your risk of stress fractures.  Although both women and men are both susceptible to low energy availability women have a lower tip point. 

Nutrition tips for women within their reproductive years

  1. Eat enough. When a women’s brain perceives that the body is not getting enough nutrition, especially carbohydrate it goes into energy save mode.
  2. Don’t train fasted. Training fasted increases cortisol which promotes fat storage and can decrease the available building blocks needed for other hormones.
  3. Eat enough carbs. Not only do eating carbs help us achieve our body composition but they also help maintain a healthy immune and stress response to exercise. 
  4. Recover quick. Eat within the hour post exercise. Ensure that you include 20-30g of protein in your post exercise snack.
  5. Start tracking. Women looking to lead a healthy lifestyle and optimise training and nutrition should track their periods and alter their training and nutrition according to hormonal phases. Apps like Flo, Clue or Spot-on can help women track their cycles. 

Nutrition tips for men through their lifespan

  1. Quality matters. With any eating pattern diet quality is key. 
  2. Do your homework. Before dabbling into any eating pattern be sure to do your homework and know why you are doing it. One size doesn’t fit all.
  3. Watch your fat intake. Focus more on the “good” plant based fats.  Eat less processed food.
  4. Dabble with intermittent fasting (IF). Metabolically IF is beneficial for men. Speak to a dietitian or a trusted health professional to help you find out which type of fasting would work best for you.
  5. Know your health numbers. Know your weight, body composition, cholesterol numbers, blood pressure and blood sugar numbers as a minimum. Knowing and tracking these numbers can improve your health.