Improved Iron Status, but Not Protein Source, Is Related to Appetite, Satiety, and Mood in Women of Reproductive Age...

Iron deficiency (ID) is associated with decreased appetite and altered mood, which can contribute to feelings of early satiety and reduced overall well-being. Few studies have examined differences in appetite, satiety, and mood between meals containing animal meat and plant-based meat, or whether improving iron status in those with ID improves these outcomes.

The objective of this study was to determine appetite, satiety, and mood after consumption of a meal containing animal meat or plant-based meat at baseline and after consuming the meal with an iron supplement once a day for 8 weeks in women of reproductive age (WRA) with ID.

In this randomized, double-blind, parallel-arm study, 52 nonpregnant WRA (24 ± 7 y; BMI: 22.9 ± 3.0 kg/m²) with ID (serum ferritin: 13.7 ± 6.0 μg/L) consumed an iron supplement with a lunch meal containing either 4 oz. of beef (Animal) or Beyond Meat (Plant) once a day for 8 weeks. Meals were calorically matched but differed in macro- and micronutrient composition due to the inherent differences between protein sources. For this secondary analysis, at baseline and endpoint, fasted participants consumed a standardized lunch meal containing beef or plant-based meat and rated appetite (fullness, hunger, desire to eat, and prospective consumption) using 100 mm visual analog scales. A composite satiety score was calculated. The Profile of Mood States questionnaire was assessed at baseline and endpoint.

Indicators of iron status and anemia improved after 8 weeks (P < 0.05 for all) but did not differ between Animal and Plant. Hunger and desire to eat decreased, and fullness and composite satiety score increased after the meal (P-time < 0.0001 for all). Measures of appetite, satiety, and mood did not differ between Plant and Animal at baseline or endpoint. Changes in transferrin saturation (r = 0.4, P < 0.01) and hemoglobin (r = 0.3, P = 0.04) and hematocrit (r = 0.3, P = 0.03) were positively associated with changes in prospective food consumption, and changes in transferrin saturation were negatively associated with satiety (r = -0.3, P = 0.02). Changes in transferrin saturation (r = 0.3, P = 0.03) and hematocrit (r = 0.3, P = 0.05) were positively associated with change in anger/hostility.

These findings indicate that improvements in iron status, but not differences in protein source, affect appetite, satiety, and mood in WRA with ID. This trial was registered at Clinicaltrials.gov as NCT04793906.