Study

LEAP Research Study: Exploring Reproductive Hormones Response to Different Diets

We are recruiting adult women with regular periods to learn more about how reproductive hormones are impacted by two different diets. We also will look at how women's hormones influence weight and metabolism.

Why this Research Matters

If you join this study, we will look at how your hormones change due to two different diets and how this affects your health. You will be put into one of two groups by chance, like flipping a coin. You don’t get to choose your group. The first group will eat a diet for 5 days that keeps your weight the same (energy balanced diet) first, then you will eat a diet with less nutrition for 5 days (low energy diet). The second group will eat the diet with less nutrition for 5 days (low energy diet) first, then will eat the diet that keeps your weight the same for 5 days (energy balanced diet). After 5 days of each diet, there will be a day of testing to look at your hormones.

What to Expect

You will have a screening visit to see if you can join the study. At this visit, we will check body measurements, take your blood, do a pregnancy test, and have you fill out several surveys. If you qualify to join, you will have four more study visits. At the first visit, we will measure your body composition by a DXA scan. This takes an X-ray picture of your body. We will also take other body measures like height and weight. At the other three visits, we will ask about your diet and activity, you will fill out surveys, we will measure your metabolic rate, and we will take blood. You will have have to eat study provided food for 5 days before your last two visits. You will also track your period and measure your fertility from home in between these visits.

Study Duration

You will have five study visits at the University of Colorado Anschutz Medical Campus. The study visits will be planned around your period. This study will last about 5 months.

Who can Participate

18 to 30 years

You may qualify for the study if you:

Are female or were born female
Aged 18-30 years old
Have a body mass index (BMI) between 30-45 kg/m²
Have had regular periods for the last 6 months
Are not using hormonal birth control
Do not have or have not had polycystic ovary syndrome (PCOS)
Are not pregnant, breastfeeding, or planning to get pregnant within the next 6 months
Are willing to keep your usual activity, diet, and weight during the study