title: Consuming Beef vs. Soy Protein Has Little Effect on Appetite, Satiety, and Food Intake in Healthy Adults.
abstract: BACKGROUND
  Although protein-rich plant foods have recently been touted as an equivalent to animal products, limited data exist regarding the effects of animal vs. plant proteins on appetite, satiety, and subsequent food intake.
  
  
  OBJECTIVE
  The objective was to determine whether a high-protein beef lunch alters the appetitive, hormonal, and neural signals controlling food intake regulation vs. a macronutrient and fiber-matched (MF) or serving size-matched (SS) soy lunch in healthy adults.
  
  
  METHODS
  A randomized, double-blind, crossover design study was completed in 21 adults (aged 23 ± 1 y; body mass index: 23.8 ± 0.6 kg/m²; mean ± SEM) to compare 400-kcal MF and SS lunches varying in protein quality. The MF lunches contained 24-g beef protein or 24-g soy protein, whereas the SS lunches contained 1 serving of beef (24-g protein/1-g fiber) or soy (14-g protein/5-g fiber). Pre- and postlunch appetite questionnaires and blood sampling were completed over an 8-h period until dinner was voluntarily requested. In addition, pre- and postlunch functional MRI brain scans were completed to assess neural activation in response to food stimuli.
  
  
  RESULTS
  On average, dinner was requested at ∼250 ± 20 min postlunch with no differences between beef vs. soy within the MF and SS conditions. Furthermore, no differences in hunger, fullness, peptide YY, or glucagon-like peptide-1 responses were observed after the beef vs. soy lunches within the MF and SS conditions. The SS beef meal led to reductions in anterior cingulate activation (-22 ± 6%) vs. soy (+7 ± 9%; P < 0.01) and greater reductions in insular activation (-30 ± 6%) vs. SS soy (-7 ± 10%; P < 0.01). The participants consumed ∼945 ± 78 kcal after the MF meals and 910 ± 74 kcal after the SS meals with no differences between beef vs. soy.
  
  
  CONCLUSIONS
  When comparing 2 high-quality protein sources, such as beef and soy, the type of protein consumed within a mixed meal elicited very little effect on appetite, satiety, and food intake in healthy adults.
authors: Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO.
authors: Steve M
authors: SM
authors: Douglas
authors: Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO.
authors: Tyler R
authors: TR
authors: Lasley
authors: Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO leidyh@health.missouri.edu.
authors: Heather J
authors: HJ
authors: Leidy
mesh_terms: D000328:Adult; D001069:Appetite Regulation; D015415:Biomarkers / Q000097:blood; D001921:Brain / Q000378:metabolism*; D018592:Cross-Over Studies; D004043:Dietary Fiber / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage*; D004311:Double-Blind Method; D002149:Energy Intake; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D062409:Lunch; D008279:Magnetic Resonance Imaging; D008460:Meat; D008923:Missouri; D009474:Neurons / Q000378:metabolism; D019894:Peptide YY / Q000097:blood; D019518:Postprandial Period; D012528:Satiety Response; D030262:Soybean Proteins / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004043:Dietary Fiber; D004044:Dietary Proteins; D030262:Soybean Proteins; D019894:Peptide YY; D052216:Glucagon-Like Peptide 1
keywords: beef; fMRI; high-protein diets; satiety; soy