Adding Unprocessed Lean Red Meat to A Healthy Vegetarian Eating Pattern Does Not Impact Short-Term Improvements in Cardiometabolic Health in Young Adults

Abstract

Abstract Objectives The 2015–2020 Dietary Guidelines for Americans recommends adopting healthy eating patterns and restricting red meat intake, whereas the impact of consuming red meat on cardiometabolic (CMD) risk factors remains inconsistent in the scientific literature. This study assessed the effects of adding unprocessed lean red meat to a lacto-ovo vegetarian eating pattern (LOV) on changes in cardiometabolic health indexes. It was hypothesized that the addition of red meat would not influence LOV-induced improvements in CMD risk factors. Methods Twenty-nine participants (15 female and 14 male, aged 26 ± 0.8 y, BMI 23.7 ± 0.4 kg/m2) completed this randomized-controlled, crossover trial. All participants consumed the same energy-balanced, LOV diet for two 3-week periods, separated by 5 weeks of habitual eating. Three ounces/day of unprocessed lean red meat (1.5 oz beef tenderloin and 1.5 oz pork loin) were added to the LOV diet without energy compensation for one of the two trials. Fasting blood pressure, serum lipids, lipoproteins, and glucose were measured before and at the end of each trial. Results were adjusted for age, sex, and body mass at each time point (LS Means ± SE, significance at adjusted P < 0.05). Results Adding unprocessed lean red meat (RM) to the LOV diet did not influence responses of the cardiometabolic health indexes after 3 weeks. Overall, significant (P < 0.05) reductions were observed for total cholesterol (without vs. with RM; −14.3 ± 3.6 vs. −14.8 ± 3.5 mg/dl), low-density lipoprotein-cholesterol (LDL-C, −8.6 ± 2.9 vs. −7.5 ± 2.9 mg/dl), and high-density lipoprotein-cholesterol (HDL-C, – 5.3 ± 1.5 vs. −4.8 ± 1.5 mg/dl). No changes were observed in fasting body mass, triglycerides, HDL-C/LDL-C ratio, glucose, or systematic/diastolic blood pressure levels. Conclusions Adopting a healthy lacto-ovo vegetarian eating pattern improves serum lipids and lipoproteins within three weeks. These improvements are retained when the eating pattern becomes omnivorous by adding unprocessed lean red meat. Funding Sources Pork Checkoff, North Dakota Beef Commission, Beef Checkoff, and Foundation for Meat & Poultry Research & Education.