07/25/2026
For decades, women were told to choose egg whites, fat-free yogurt, dry salads, and “light” everything… then we wonder why so many are struggling with blood sugar swings, cravings, low libido, cycle issues, hormone imbalances, and fertility challenges.
Reproductive hormones don’t appear out of thin air. Estrogen, progesterone, and testosterone are steroid hormones, and the body requires adequate energy, cholesterol, and essential fatty acids to support normal hormone production.
And yes, we have data on this:
In women, studies on low-fat diets have found that they circulating estrogen (20-30%) and progesterone levels (35-53%). Guess what your body can't do without sufficient estrogen and progesterone? Ovulate! This tracks with the data we have on women with hypothalamic amenorrhea; the macronutrient they're most likely to restrict is dietary fat.
For men, a systematic review/meta-analysis of intervention studies found that low-fat diets significantly reduced total testosterone, free testosterone, urinary testosterone, and DHT compared with higher-fat diets.
Now, quality matters. That's a conversation I cover in a ton of detail in Real Food for Fertility. But the blanket fear of fat is not helping.
Fertility is metabolically demanding. Hormone production is nutritionally demanding. Trying to make hormones, let alone build a baby on a diet designed to keep calories and fat as low as possible was never a good plan.
Did you ever fear dietary fat? How did it affect you?
All studies mentioned in this post are covered in more detail in Real Food for Fertility. Reply SPARK for more info on the book.
