Effects of Lean Pork, High Protein Breakfast on Satiety and Metabolic Health in Pre-diabetes

This is a randomized, crossover trial that includes two screening visits, one baseline visit, and two test periods of 2 weeks each, each ending with a test visit, separated by a 2-week washout. Subjects consume each day a refined carbohydrate-rich breakfast containing 8/66/26% kcal from protein/carbohydrate/fat, respectively (Control Condition), or a high pork protein breakfast containing 35/39/26% kcal from protein/carbohydrate/fat, respectively (Active Condition). Study products for daily breakfast consumption will be dispensed to the subjects at the beginning of each test period. Subjects will complete 3-day diet records at baseline and the end of each test period, and a daily Appetite Visual Analog Scale (VAS) Diary to asses perceived hunger and fullness each evening before retiring throughout each test period. VAS assessments of hunger, fullness, desire to eat, prospective food consumption, focus and energy will also be assessed at the clinic visit at the end of each test period, pre- and post-breakfast consumption (multiple time points). Subjects will also complete a palatability questionnaire at the each of each test period. Blood samples will be collected at fasting at baseline and pre- and post-breakfast consumption (multiple sampling) at the end of each test period to evaluate glucose, insulin, and lipoprotein lipid concentrations.

Inclusion criteria

• Body mass index 25.0-39.9 kg/m2
• At least 1 of the following: a) capillary glycated hemoglobin 5.7-6.4%, b) fasting capillary glucose 100-125 mg/dL, or c) capillary glycated hemoglobin <5.7% and borderline fasting capillary glucose level 95-99 mg/dL and a subsequent fasting venous plasma glucose 100-125 mg/dL
• Self-identified "regular breakfast consumer" and willing to eat study foods as a breakfast meal
• Access to freezer and a food re-heating appliance
• Judged to be in good health on basis of medical history

Exclusion criteria

• Fasting laboratory test results of clinical significance (e.g., triglycerides ≥500 mg/dL, capillary glucose ≥126 mg/dL, glycated hemoglobin ≥6.5%)
• Uncontrolled hypertension
• Recent major trauma or surgical event
• Recent weight change ≥4.5 kg
• History or presence of clinically important endocrine, cardiovascular, pulmonary, biliary, or gastrointestinal disorders
• Recent history or presence of cancer (except non-melanoma skin cancer)
• History of extreme dietary habits
• Vegan or vegetarian
• History of eating disorder diagnosed by health professional
• Known intolerance or sensitivity to study products
• Unstable use of medications intended to alter lipid profile (e.g., unstable use of statins, bile acid sequestrants, cholesterol absorption inhibitor, fibrates, niacin-drug form, or omega-3-acid ethyl ester drugs)
• Recent use of foods or dietary supplements that might alter lipid metabolism (e.g., omega-3 fatty acid supplements or fortified foods, sterol/stanol products, pantethine, viscous dietary fiber supplements, red yeast supplements, garlic supplements, soy isoflavone supplements, probiotic supplements, niacin or analogues at >200 mg/d)
• Recent use of medications known to influence carbohydrate metabolism (e.g., adrenergic blockers, diuretics, hypoglycemic medications, systemic corticosteroids)
• Recent use of weight-loss drugs (including over-the-counter) or programs
• Recent history or current use of supplements and/or medications known to influence, satiety, appetite, taste, sense of smell, or weight (e.g., hypoglycemic medications and systemic corticosteroids)
• Recent use of antibiotics
• Signs or symptoms of active infection of clinical relevance
• Current or recent history of drug or alcohol abuse
• Pregnant, planning to be pregnant, or lactating females or women of childbearing potential unwilling to commit to use of a medically approved form of contraception