Weight fluctuations - for women · Breakthrough Body Blueprint

Weight fluctuations - for women

I've been seeing some posts on frustrations due to weight fluctuations for women and thought I could share some information I learned long time ago, when I first started tracking my weight.

I hope this helps to reassure those who are worried, and help take off some of the mental pressure we put on ourselves everytime we step on the scale. 🩷

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Weight fluctuations throughout the menstrual cycle are completely normal and are primarily driven by hormonal changes rather than changes in body fat. Most women experience a fluctuation of 2 to 6 pounds (roughly 1–3 kg) over the course of a 28-day cycle.

The graph below illustrates how weight typically changes in relation to the four main phases of the cycle and the primary hormones involved, Estrogen and Progesterone.

Key Phases of Weight Fluctuation

*** Menstrual Phase (Days 1–5):

Trend: Weight is usually at its peak on Day 1 but begins to drop rapidly.
Reason: As your period starts, levels of estrogen and progesterone drop. This signals the body to release the water it was holding onto during the previous week. By the end of menstruation, most women return to their "baseline" weight

*** Follicular Phase (Days 6–13):

Trend: Weight is typically at its lowest and most stable.
Reason: Estrogen is the dominant hormone here. It acts as a natural appetite suppressant and can improve insulin sensitivity, making this the phase where many women feel "leanest" and have the most energy for workouts.

*** Ovulation (Day 14):

Trend: A slight, temporary "bump" in weight.
Reason: A sharp peak in estrogen just before ovulation can cause a brief period of bloating and water retention. This usually resolves within 24–48 hours.

*** Luteal Phase (Days 15–28):

Trend: Steady weight gain, peaking right before the next period.
Reason: Progesterone rises significantly. This hormone triggers the kidneys to retain more salt and water (bloating). Additionally, progesterone can increase metabolic rate (burning 100–300 more calories/day) but also increases appetite and cravings for high-carb/sugary foods, which can further contribute to temporary water weight.

Why does this happen?

Water Retention: Progesterone and estrogen affect how your body regulates sodium. High levels lead to "leaky" capillaries that allow fluid to move into your tissues, causing that puffy feeling (edema).
Digestion: High progesterone can slow down the digestive tract, leading to constipation and gas, which increases the number on the scale and the feeling of heaviness.
Magnesium: Dropping magnesium levels before a period can cause sugar cravings and further water retention.

~~~ Takeaway: If you are tracking your weight for fitness goals, it is often most accurate to compare your weight to the same day of your previous cycle (e.g., comparing Day 5 to Day 5) rather than comparing Day 5 to Day 25. ~~~

That's why I've learned to stop focusing on the numbers of the scale & compare body measurements instead.

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