Effects of Protein Timing and Resistance Exercise on Fat Metabolism
Condition: Healthy
Study type: Interventional

Summary: 
      The extent to which resistance exercise training and protein timing effects localized (belly
      fat) and systemic (whole body) fat metabolism in resistance-trained women is unknown.
      Therefore, this study will assess subcutaneous abdominal adipose tissue lipolytic rate and
      whole body substrate utilization over the course of two trials: 1) consuming casein protein
      during the day, and 2) consuming casein protein at night, before bed.
    

Detailed description: 
      Nighttime eating, and specifically eating after dinner, has attracted significant attention
      in recent years, particularly for the onslaught of media claiming the negative implications
      on body weight and overall health. Some studies have indeed indicated that chronically eating
      high-energy, mixed-meals rich in carbohydrates (CHO) and fats at night contributes to weight
      gain and abdominal obesity. However, research to support these negative claims is scant.
      Conversely, the practice of nighttime eating of small protein (PRO) snacks has been widely
      utilized anecdotally in populations such as bodybuilders in an attempt to avoid catabolism of
      muscle mass during the sleeping hours.

      It has been shown that nighttime consumption of small portions (<200 kcals) of PRO elicits
      beneficial effects on metabolism such as increased next-morning resting metabolic rate (RMR).
      Likewise, the combination of nighttime PRO consumption and RT improves factors that
      contribute to fat loss such as elevated muscle mass due to an increase in muscle protein
      synthesis and energy expenditure. Further, there is emerging research suggesting the benefits
      of nighttime PRO consumption on fat metabolism (specifically the subcutaneous abdominal
      adipose tissue [SCAAT]). The SCAAT is of particular interest in metabolism research, as the
      upper body subcutaneous tissue (i.e. SCAAT) supplies most of the circulating free fatty acids
      (FFA) during the overnight hours in lean individuals. Therefore, if one can optimize the
      timing of dietary PRO during a window at which SCAAT is elevated (nighttime), theoretically,
      mobilization and oxidation of fats could be optimized.

      Research regarding nighttime eating, specifically regarding fat metabolism, is in its
      infancy, and thus, many gaps in the literature require elucidation. First, and certainly most
      importantly, the limited research studies examining the effects of nighttime PRO consumption
      have not methodologically matched for timing of PRO intake. Therefore, it is unclear whether
      any reported benefits of the published nighttime PRO studies were a consequence of the
      addition of PRO calories or specifically due to the consumption of PRO at night. Thus, in
      order to make optimal comparisons and conclusions, it is imperative to study the metabolic
      effects of dietary PRO consumed at night versus other times of day.

      Therefore, the purpose of this project is to: 1) determine the effects of RT on post-exercise
      lipolytic rate in resistance-trained women; and 2) determine the effects of timing of acute
      protein PRO ingestion (nighttime PRO consumption [NP] and daytime PRO consumption [DP]
      trials) after a RT bout on SCAAT lipolytic rate, metabolic rate, and serum hormones (glucose,
      insulin, growth hormone, adiponectin, glycerol) throughout the day, overnight and into the
      next morning.
    

Intervention name(s): Micellar Casein Protein; Resistance Exercise Training
Intervention type(s): Dietary Supplement; Other
Intervention description(s): The micellar casein protein supplement (PRO, total protein content: 30 g, 120 kcals; 30 g micellar protein) and non-caloric sensory-matched placebo (PLA, 0kcals) will be specifically formulated by Dymatize® Nutrition FrieslandCampina® and consumed in a randomized order. Participants will consume the daytime supplement 30 minutes after RT and the nighttime supplement about 30 minutes before bedtime. The supplements will be premixed, taste-matched (chocolate), and provided in opaque shaker bottles.; Resistance exercise training (RT) will target the full body and exercises will be performed using a barbell. Exercises will be performed in the following order: back squat, bench press, Romanian deadlift, bent-over row, shoulder press, and reverse lunges)
Intervention MeSH terms: Caseins
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized, crossover, double-blind, acute study with two conditions: nighttime PRO consumption (NP) and daytime PRO consumption (DP).
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: protein; lipolysis; fat oxidation; resistance training; nutrient timing