Athletes who do weight training and want to lose weight can keep their appetite under control – and therefore also increase the chance of their weight-loss attempt actually succeeding – by drinking a shake containing 20 g whey an hour before a meal. Higher doses don’t work any better, Australian researchers discovered.
The slimming effect of protein
If you want to lose weight, you need to consume more protein and less carbohydrate and fat. The satiating effect of protein means you’ll eat less and that your body burns a little more energy.
You can increase the protein portion of your diet by consuming a whey shake between meals. But how much protein should the shake contain? That’s the question that the Australians, who worked at the Queensland University of Technology, set out to answer.
The researchers performed an experiment using ten male athletes. The men played rugby, football or soccer, and also did weight training three times a week.
The subjects had to come to the researchers’ lab on four different mornings. There they were given breakfast, an hour later a whey shake and a couple of hours later lunch. The shake contained on one occasion 20 g whey, the next time 40 g whey, the time after than 60 g and the last time 80 g whey.
The researchers then measured how much the subjects ate during their lunch. As you can see below, it didn’t matter much how much whey the subjects had consumed. They ate the same amount of lunch after a shake containing 20 g whey as they did after a shake containing 80 g whey.
During the days that the subjects spent in the lab they also had to indicate how hungry they were on a number of occasions. This way the researchers were able to work out how feelings of hunger increased after breakfast – and how the shake suppressed the subjects’ appetite.
That’s how they learned that the amount of whey in the shake didn’t make any difference: all doses suppressed feelings of hunger equally.
The effect of a whey protein supplement dose on satiety and food intake in resistance training athletes.
Many athletes perform resistance training and consume dietary protein as a strategy to promote anabolic adaptation. Due to its high satiety value, the regular addition of supplemented dietary protein could plausibly displace other key macronutrients such as carbohydrate in an athlete’s diet. This effect will be influenced by the form and dose of protein. Therefore, this study assessed the impact of liquid whey protein dose manipulation on subjective sensations of appetite and food intake in a cohort of athletes.
Ten male athletes who performed both resistance and aerobic (endurance) training (21.2 ± 2.3 years; 181.7 ± 5.7 cm and 80.8 ± 6.1 kg) were recruited. In four counter-balanced testing sessions they consumed a manipulated whey protein supplement (20, 40, 60 or 80 g protein) 1 hour after a standardised breakfast. Subsequent energy intake was measured 3 hours after the protein supplement using an ad libitum test meal. Subjective appetite sensations were measured periodically during the test day using visual analogue scales.
All conditions resulted in a significant decrease in ratings of hunger (50-65%; P < 0.05) at the time of supplement consumption. However, there were no significant differences between the conditions at any time point for subjective appetite sensations or for energy consumed in the ad libitum meal: 4382 ± 1004, 4643 ± 982, 4514 ± 1112, 4177 ± 1494 kJ respectively. CONCLUSION: Increasing whey protein supplement dose above 20 g did not result in a measurable increase in satiety or decrease in food intake. However, the inclusion of additional whey protein supplementation where not otherwise consumed could plausibly reduce dietary intake. PMID: 25979566 [PubMed - in process] Source: http://www.ncbi.nlm.nih.gov/pubmed/25979566