Assistant Professor of Exercise Science Takudzwa “Titch” Madzima and Associate Professor of Exercise Science Svetlana Nepocatych have published a new study in the journal Nutrients with Jared Melanson ’17 and Jonas Black ’17 showing that 48 grams of casein protein consumed prior to sleep likely has favorable metabolic effects in active women.
Assistant Professor of Exercise Science Takudzwa “Titch” Madzima and Associate Professor of Exercise Science Svetlana Nepocatych have published a new study with Jared Melanson ’17 and Jonas Black ’17 showing that 48 grams of casein protein consumed prior to sleep likely has favorable metabolic effects in active women.
The article titled in “Pre-Sleep Consumption of Casein and Whey Protein: Effects on Morning Metabolism and Resistance Exercise Performance in Active Women” in Nutrients, a top nutrition journal. This work is part of a research line investigating the consumption and timing of different macronutrients (protein, carbohydrates and fats) on energy metabolism and body composition.
Pre-sleep feeding, also referred to as nighttime eating, is defined as the consumption of nutrients (calories) within 30-60 minutes of going to sleep. Previous concerns about nighttime eating have been largely anecdotal and based on the concept that eating late at night leads to weight gain.
While the concern of weight gain is understandable since metabolic rate (the energy your body burns when it is at rest) is slower at night, it is important to note that the metabolic rate does not stop overnight. This old perspective is based largely on observational studies in populations such as nightshift workers who consume a majority of their calories in close proximity to sleep, but not on small (~160 kcals), nutrient dense snacks like protein supplements or cottage cheese.
Recently, this time period has been considered a new window of opportunity in nutrient timing research as previous work from Madzima and colleagues have shown that pre-sleep consumption of low calorie (~160 kcals) protein or carbohydrates to increase morning metabolic rate in active men, and did not hinder fat oxidation (burning fat as a fuel source). Several recent studies have also shown that pre-sleep casein protein, a slow digesting milk protein, is properly digested and absorbed overnight, promotes overnight recovery and does not hinder your ability to burn fat as a fuel source.
In this new study, Madzima and colleagues sought to investigate whether pre-sleep consumption of two commonly consumed milk protein supplements, casein and whey, at different doses would have favorable effects on resting metabolic rate and exercise performance the following morning as a result of improved overnight recovery.
The rationale for measuring exercise performance the next morning is that many adults who exercise in the morning do not have the time to eat a meal, let it digest and then go exercise before work. Therefore, consuming a small snack or supplement prior to sleep the night before may provide the energy necessary to perform exercise the next morning without having breakfast.
This study found that only 48 grams of casein protein increased next morning metabolic rate and while only trivially improving next morning resistance exercise performance in active women. The other doses (24 grams) of casein and whey (24 grams and 48 grams) protein had unclear effects.
Taken together, these findings suggest that pre-sleep consumption of protein snacks (~120-240 kcals) does not have adverse metabolic effects, nor does it hinder next morning resistance exercise performance and fat oxidation in active women. Overall pre-sleep feeding may be a beneficial strategy to provide nutrients during the overnight period to favorably alter metabolism and possibly promote overnight recovery in active women.