Obesity
Conditions
Keywords
obesity, overweight, muscle, protein, muscle protein synthesis, muscle protein breakdown, whey, soy, caloric restriction
Brief summary
It is known that dieting (restricted energy intake) without resistance training leads to a reduced metabolic rate, and the loss of both fat and muscle mass. When exercise is not included in a period of restricted energy intake, the degree to which muscle mass is lost is highly dependent upon protein consumption. Whey protein is a high quality protein isolated from milk and is known to stimulate new protein synthesis for all proteins in your body. Previous research has established that the consumption of whey protein has been correlated with retaining muscle mass while stimulating fat loss. However, the mechanisms behind these findings is still unknown. The purpose of this study is to establish a mechanistic underpinning to the efficacy of whey protein versus soy protein and a carbohydrate control (maltodextrin), in promoting fat mass loss and lean mass retention during a period of short-term controlled dietary energy deficit (-750 kcalories/day).
Interventions
Sponsors
Study design
Eligibility
Inclusion criteria
* Aged 35 to 55 years old * Moderately Obese/Overweight (body mass index \> 25 and \< 42 kg/m2) * Healthy * Non-smoker
Exclusion criteria
* Suffer from type 2 diabetes, hyperlipidemia, or thyroid dysfunction * Taking medications * Having an unstable weight in the past 4-6 months, or dieting at some time during the past 6 months * Taking weight loss products or aids (including energy drinks)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Muscle protein synthesis rate and lipolytic rate as measured using stable isotope and glycerol infusions. | After 14 day dietary intervention |
Secondary
| Measure | Time frame |
|---|---|
| Transcriptomic changes (via gene profiling) associated with the effects of whey on lipogenic and lipid oxidative genes, and protein synthetic pathways in muscle. | After 14 days of dietary intervention |
Countries
Canada