Disproportionate Use of Over-the-counter Diet Pills Among Latinx Youth and Increased Use Over Time Among Latinx Females: Results of US National Study

Abstract

Purpose:

Over-the-counter diet pills are target-marketed to Latinx communities, raising concerns about youth use of these harmful products.

Methods:

Multivariable logistic models estimated odds ratios (ORs) of diet-pill use in a representative sample of US Latinx and White students (2009–2013; N = 33,824).

Results:

Latinx students had 30%–40% higher odds of past-30-day diet-pill use than White peers (males: OR = 1.39; 95% confidence interval = 1.10, 1.76, females: OR = 1.34; 95% confidence interval = 1.12, 1.61), and inequities among females widened, with one in 10 Latinx females reporting past-30-day use by 2013 (10.0% Latinx females vs. 6.2% White non-Latinx females).

Discussion:

Higher prevalence of over-the-counter diet-pill use in Latinx relative to white youth—and increasing use over time for Latinx females—underscores the need for stronger restrictions on marketing and sale to youth.

Manufacturers of over-the-counter (OTC) diet pills have faced US federal charges for deceptive weight-loss claims and predatory targeting of Latinx communities [1–3]. Weight-loss dietary supplements have been linked to serious adverse health effects [4–6]. OTC diet-pill use differs by gender and income [7] and has been associated prospectively with the onset of eating disorders in youth [8]. Latinx females have higher risk for disordered eating behaviors than White females [9]. Despite this, recent OTC diet-pill use among Latinx youth is unknown. This study aimed to estimate change in the prevalence of OTC diet-pill use from 2009 to 2013 among US Latinx and White youth.

Methods

We used data from the Youth Risk Behavior Surveillance System (YRBSS), a national survey administered by the Centers for Disease Control and Prevention (CDC) using a three-stage cluster sample design to produce a nationally representative sample of US private and public high school students in grades 9–12 [10]. Our sample included 12,781 Latinx and 18,509 White non-Latinx students over three survey years (2009, 2011, and 2013) before exclusions for missing data (sex: n = 31, OTC diet-pill use: n = 430, and age: n = 14). After 2013, the CDC stopped requiring states to include a question on OTC diet-pill use on YRBSS surveys. After excluding missing data, weighting of the sample was used to account for over-sampling of Latinx students in the YRBSS, creating a final analytic sample of 8,655 Latinx and 25,169 White students. Students self-reported their sex (male/female), age, and race/ethnicity (any race “Hispanic/Latino”/“White”; herein, Latinx/White non-Latinx). OTC diet-pill use was assessed by the yes/no question: “During the past 30 days, did you take any diet pills, powders, or liquids without a doctor’s advice to lose weight or to keep from gaining weight? (Do not include meal replacement products such as Slim Fast.)” Sex-stratified, multivariable logistic models estimated odds ratios (ORs) and 95% confidence intervals (CIs) of past-30-day OTC diet-pill use. First, main-effect models were fit with race/ethnicity as the primary predictor, controlling for age and the survey year. Models were then fit with a race/ethnicity-by-survey-year interaction term. All models were weighted to account for the complex survey design of the YRBSS [10]. This research was granted exempt status from the University of Massachusetts Medical School Institutional Review Board.

Results

Table 1 presents past-30-day OTC diet-pill use by race/ethnicity, sex, and survey year. The age of study population included high school students, with most of Latinx females and males aged 15–16 years and most of White non-Latinx females and males aged 16–17 years. Combining across the three survey years, reports of past-30-day diet-pill use were more common among Latinx females (8.2%) and males (4.6%) than those among White non-Latinx females (6.3%) and males (3.5%). Evidence of a widening racial/ethnic inequity was found among females but not males over time. In 2009, diet-pill use was reported by 6.9% of Latinx and 7.0% of White non-Latinx females and 4.6% of Latinx and 3.6% of White non-Latinx males. By 2013, the prevalence remained relatively stable for males in both racial/ethnic groups and for White non-Latinx females but increased to 10.0% for Latinx females (Figure 1).

Table 1.

Past-30-day over-the-counter diet-pill use by race/ethnicity and sex from the YRBSS, 2009–2013 prevalence (N = 33,824)

Past-30-day prevalence by race/ethnicity and sex, n (%)
	2009	2011	2013
Latinx (n = 8,655)	168 (5.7)	190 (6.4)	195 (7.1)
White non-Latinx (n = 25,169)	481 (5.2)	408 (4.7)	335 (4.6)
Females (n = 16,388)
Latinx	101 (6.9)	112 (7.8)	139 (10.0)
White non-Latinx	301 (7.0)	241 (5.8)	243 (6.2)
Males (n = 17,436)
Latinx	67 (4.6)	77 (5.0)	56 (4.2)
White non-Latinx	180 (3.6)	162 (3.7)	111 (3.0)
	OR	CI	p valueb
Main-effect modelsa
Latinx females	1.34	1.12–1.61	.002
Latinx males	1.39	1.10–1.76	.007
Interaction modelsa
Females
Latinx	0.78	0.53–1.14	.20
Survey year	0.93	0.80–1.08	.319
Race/ethnicity × survey year interaction	1.31	1.06–1.63	.014
Males
Latinx	1.30	0.78–2.16	.317
Survey year	0.91	0.76–1.08	.281
Race/ethnicity × survey year interaction	1.04	0.81–1.33	.779

Bold p values indicate significance at p < .05.

CI = 95% confidence interval; OR = odds ratio; YRBSS = Youth Risk Behavior Surveillance System.

^aOdds ratios are derived from sex-stratified multivariable logistic models adjusted for age and the survey year and weighted to be representative of high school students in public and private schools in the United States. For all main-effect and interaction models, White non-Latinx was used as the reference for all comparisons.

^bObtained from Wald tests.

Figure 1.

Trends in past-30-day over-the-counter diet-pill use by race/ethnicity in females and males from the Youth Risk Behavior Surveillance System, 2009–2013 (N = 33,824).

In the multivariable main-effect models, Latinx males and females had approximately 30%–40% higher odds of past-30-day diet-pill use than their same-sex White non-Latinx peers (males: OR = 1.39; 95% CI = 1.10, 1.76, p = .007; females: OR = 1.34; 95% CI = 1.12, 1.61, p = .002). Furthermore, among females but not males, the interaction between the race/ethnicity and the survey year in the interaction models was statistically significant (OR = 1.31; 95% CI = 1.06, 1.63, p = .014), indicating that the inequity between Latinx and White non-Latinx females widened over the study period.

Discussion

We found that Latinx students have 30%–40% higher odds of past-30-day diet-pill use than their same-sex White non-Latinx peers and that racial/ethnic inequities among females widened from 2009 to 2013. Racial/ethnic inequities in diet-pill use may be in part attributable to the industry’s targeting of the Latinx community, which has intensified in recent years. In 2016, the US Federal Trade Commission charged Herbalife, a major manufacturer of weight-loss supplements, with deceptive practices. Although Herbalife settled that lawsuit, multiple lawsuits claiming continued deception have been filed against the company as recently as summer 2020 [2,11].

Weight-loss dietary supplements are not medically recommended, have limited oversight from the US Food and Drug Administration [5,12], and have been shown to be prospectively associated with eating disorder onset [8]. Despite these concerns, the CDC ceased surveillance of OTC diet-pill use on the YRBSS after 2013, without explanation. Ongoing, systematic national surveillance through the YRBSS and other public health tools are needed to properly monitor trends in OTC diet-pill use, especially among youth, and to evaluate the impact of consumer protections and interventions aiming to reduce OTC diet-pill use.

Limitations of our study include more than eight-year-old data due to cessation of CDC surveillance of OTC diet-pill use and lack of data on gender, specific Latinx ethnic background, and OTC diet-pill use duration, dose, or product used. However, an important strength is that we analyzed time-series data across an important period of predatory targeting of the US Latinx community by the OTC diet-pill industry [13] within a representative sample.

Our findings underscore an under-recognized threat to the health of US Latinx youth. Stronger policies must directly address and restrict industry predatory practices, especially those targeting Latinx communities. Furthermore, interventions within educational and health care settings are needed to assess and reduce OTC diet-pill use among youth, and the CDC should reintroduce assessment of OTC diet-pill use via public health surveillance systems.

IMPLICATIONS AND CONTRIBUTIONS.

Over-the-counter (OTC) diet pills pose adverse health risk to youth owing to adulteration with dangerous ingredients and aggressive target-marketed to Latinx communities. An analysis of three waves of Youth Risk Behavior Surveillance System data showed higher prevalence of OTC diet-pill use among Latinx than among White youth and increasing use from 2009 to 2013 in Latinx females.