Background

Aspects of diet have been associated with infertility. However, it is unclear whether dietary energy (kcal), energy density (kcal/g), nutrient composition (e.g., added sugar, sodium, saturated fat), or industrial processing itself influence fertility. There is a paucity of data regarding the influence of food processing on reproductive outcomes. This study tests the hypothesis that women with lower processed food intake, rather than lower energy or specific macronutrient intake, would have increased successful egg transfer and pregnancy following in-vitro fertilization (IVF).

Methods

Participants (n=28) from a university IVF clinic completed three-day diet records that were analyzed using the Nutrition Data System for Research. Output was classified into the four NOVA food groups; 1) unprocessed, 2) processed culinary ingredients, 3) processed, and 4) ultra-processed. Using ANOVA, we compared dietary energy, energy density, and nutrient composition between the NOVA food groups and quantified differences between the intake of women with and without successful egg transfer and pregnancy.

Results

Participants consumed 1960 ± 664 kcal/day (35% fat: 45% carbohydrate: 16% protein). There were no differences in energy intake, energy density or macronutrient composition for those with successful egg transfer or pregnancy versus those without. Women with successful egg transfer consumed more calories per day from unprocessed (group 1) foods (p < 0.05). Women who became pregnant consumed fewer servings per day of ultra-processed (group 4) foods (p < 0.05).

Conclusions

These findings suggest that processed food intake, rather than energy or macronutrient intake, may influence fertility and IVF outcomes.