Obesity is recognized as a major public health concern because of its link to potential fatal complications arising from metabolic and cardiovascular diseases. Despite many pharmacological advances in this field, lifestyle strategies that emphasize proper nutrient intake and physical activity continue to be the primary strategy for individuals to fight obesity. However, controversy exists regarding the type and timing of exercise and specific nutrient intake to maximize fat loss, muscle gain, and beneficial cardio-metabolic adaptations derived from these lifestyle interventions. Furthermore, limited data exists investigating the impact of nutrient timing at times other than immediately before or after exercise and no studies have examined time-of-day nutritional intake in overweight or obese individuals.In addition, many individuals attempting to improve body composition and cardio-metabolic health are concerned with what food choices are appropriate in the late evening to support positive physiological adaptations. However, research-based information examining this topic is scarce. The investigators hypothesize that consumption of a protein beverage in the late evening before sleep will improve body composition, cardio-metabolic health, and adaptations to exercise more than an isocaloric placebo beverage. The investigators also hypothesize that the different digestion and absorption kinetics of whey and casein proteins will elicit different effects on the measures variables.
The purpose of this study is to examine the effect of consumption of a protein beverage in the late evening before sleep along with the combination of resistance and high-intensity interval training on improving body composition, muscle strength and overall health compared to a carbohydrate placebo beverage in overweight and obese individuals. Specifically, we will be measuring heart rate, blood pressure, body composition, resting metabolism, maximal strength,cardiovascular function, hormones levels, blood lipid profile, appetite, mood state, and dietary intake. Specific aims of the study are: To determine if acute ingestion of a liquid ready-to-drink protein supplement (30g whey or casein protein per serving) consumed in the late evening before sleep will alter the physiological milieu to favor anabolism and alter lipolysis and fat oxidation more than the carbohydrate placebo (34g of maltodextrin per serving). To determine if 4 weeks of daily protein supplementation (same supplement as above) in the late evening along with 3 days of exercise training per week will improve body composition, blood lipid profile, strength, cardiovascular risk profile more than a placebo beverage.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
59
Whey protein will be consumed every night of the week as the last food or caloric beverage prior to sleep in the evening at least two hours after dinner but no more than 30 minutes before bed.
Completed 3 d/wk for 4 wks (2 d of Resistance Training (RT) and 1 d of High-Intensity Interval Training (HITT)). RT exercises were chest press, seated row,leg press, shoulder press, leg extension, and leg curl (3 total sets: 2 sets of 10 repetitions and a 3rd set to muscular exhaustion with a load equaling 75-85% of 1-Repetition Maximum(RM)). All exercises and sets were separated by 90-120 sec of rest. HIIT training was completed on commerical cardiovascular equipment and requires subjects to rate their perceived exertion on a scale from 1 to 10 (1= resting quietly, 5= a warm-up level, 10= an all-out exertion). Subjects warmed-up for 2 min at level 5 and increased their exertion each min for 3 min until level 9 is perceived and then recover at level 6 for 1 min. This pattern was repeated 4 times, where the 4th cycle subjects increased their last min of exertion to level 10, followed by 1-min recovery at the initial warm-up level 5.
Casein protein will be consumed every night of the week as the last food or caloric beverage prior to sleep in the evening at least two hours after dinner but no more than 30 minutes before bed.
Florida State University
Tallahassee, Florida, United States
Body Composition
Measuring fat mass and lean mass from dual-energy x-ray absorptiometry.
Time frame: 4 weeks
Metabolism
Measured using indirect calorimetry, a non-invasive test that involves lying down on a padded table for 30-minutes with a mouth piece and nose clip
Time frame: 4 weeks
Blood biomarkers
Under sterile conditions 20 milliliters of blood was drawn from a forearm antecubital vein and analyzed for blood biomarkers.
Time frame: 4 weeks
Arterial Stiffness
Measured using pulse wave velocity of the aorta, systemic, and legs
Time frame: 4 weeks
Appetite
Measured by a visual analog scale
Time frame: 4 weeks
Strength
Assessed by having the subject progressed towards the maximum weight that they can lift 1-time through a full range of motion and all attempts and will be supervised by trained personnel
Time frame: 4 weeks
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