Body fat, dietary fat & women - are we friends or enemies?


DIETARY FAT


First of all, what is fat?

Fat is one of 3 macronutrient groups that are essential for optimal functioning of a human body. Together with carbohydrates & proteins, fat has many jobs in the body.


What are the functions of fat?

  • Providing energy (or storing it for later). 1 gram of fat contains 9 kcal.

  • Carrying fat-soluble vitamins (A,D,E & K) and supporting their absorption in the intestines.

  • Making up fatty tissues such as eyes, brain (nearly 60% of the brain is made of fat) & membranes around cells.

  • Controlling signalling and inflammation by regulating molecules such as prostaglandins. Prostaglandins control processes such as inflammation, blood flow, the formation of blood clots and the induction of labour.

  • Secretion of leptin - the satiety hormone.

  • Making steroid hormones, which include:

  • Sex hormones (estrogen, progesterone, testosterone, etc.).

  • Cortisol- the primary stress hormone.

  • Aldosterone - it’s main role is to regulate salt and water in the body, thus having an effect on blood pressure.

  • Keeping skin soft.


How much fat do we need?

For most women the optimal fat intake would be at 20-35% of their daily energy requirement. Keeping saturated fats at about 10 per cent or less of the fat intake.


High Fat Diets (HFD) & Fertility.

Some evidence suggests that HFD impairs female reproductive function, both with and without obesity. When the obese phenotype is present though, the effect is worsened.

Many cases of obesity result from overconsumption of fat. High dietary fat intake, with or without the development of obesity, impairs female hypothalamic-pituitary-ovarian (HPO) axis functionality and fertility.*



BODY FAT


Healthy female’s body fat level according to WebMed is: Essential fat 10-12%

Athletes 14-20%

Fitness 21-24%

Acceptable 25-31%

Obese 32% plus

Body fat percentage & hunger

Body fat percentage correlates to the amount of leptin in the body.

When body fat decreases, leptin also decreases. When leptin decreases, hunger tends to increase because leptin tells our brain we do not have enough fuel stored in the body fat.

When body fat increases, leptin also increases. When leptin increases, hunger tends to decrease because leptin tells our brain we have enough fuel stored in the body fat.


Body fat percentage & absence of menstruation or irregular menstruation :


Both absence of menstruation (Amenorrhea) and infrequent or irregular menstruation (Oligomenorrhea) can result from lowered hormone production. This can be due to stress resulting from chronic energy deficit, restrictive diet or heavy training load.

Functional Hypothalamic Amenorrhea (FHA) occurs when the ovaries work just fine, but part of the brain called hypothalamus stops sending signals to ovaries to produce sex hormones such as estrogens and progesterone. FHA can happen when a woman's body fat is too low and the brain thinks that this is not a good time to get pregnant.



*High-Fat Diet and Female Fertility- Natalie M. Hohosand , Malgorzata E. Skaznik-Wikiel 2017 Aug 1 PMCID: PMC6283234


Body fat, dietary fat & women - are we friends or enemies?
Body fat, dietary fat & women - are we friends or enemies?