Predictors of protein intake among people who inject drugs in Los Angeles and San Francisco, California

Background and Objectives While inadequate nutrition can weaken the immune system and lead to negative health sequelae for vulnerable populations, little is known about nutritional intake among people who inject drugs (PWID). We aimed to quantify nutritional intake among PWID and to explore associations between protein intake and drug use. Methods A cross-sectional design was used to analyze self-reported participant data. PWID were recruited from community settings in California in 2016/2017. Participants reported on food consumption per day for a 30-day period, from which a continuous protein intake variable was created. Results Modal characteristics of participants (N = 937) were: white (42.5%), male (75.3%), healthy body mass index (BMI) (56.6%), and unhoused (82.9%). Less than 1% of participants met or exceeded recommended guidelines for protein intake (0.80 g/day/1 kg body weight). The final multiple regression model found protein intake to be significantly positively associated with older age, high school or greater education, frequency of opiate and marijuana use, while Latinx ethnicity was inversely associated with protein intake, adjusting for gender. Discussion and Conclusions Our study shows PWID are generally not underweight, yet they are grossly protein deficient, which can be harder to recognize. Poverty, homelessness, and other structural barriers likely contribute to this issue, which demonstrates the need for communities to provide more access to nutrient-rich food to PWID. Scientific Significance Our study demonstrates the novel findings that opiate and marijuana use frequency, but not stimulants (methamphetamine and cocaine) may increase preference for protein-rich foods among PWID.