None listed
Conditions
Brief summary
It is widely accepted that consumption of protein is more satiating than carbohydrate or fat (lower food intake at a subsequent meal and lower subjective ratings of appetite), but the satiating effect of protein is thought to be source dependent. As the speed at which proteins are digested in the stomach and the building blocks of proteins, amino acids, are absorbed in the small intestine, differ among proteins, proteins have been grouped into either “fast” proteins, which are rapidly digested, or “slow” proteins, which form clots in the stomach and are therefore slowly digested and absorbed. In this study, the effects of two "slow" proteins (zein, a protein originating from maize, and casein, a dairy milk protein), two "fast" dairy milk proteins (whey protein and alpha-lactabumin), and a carbohydrate (maltodextrin, a simple carbohydrate) control on subsequent food intake at a test meal, subjective measures of satiety, and circulating amino acid responses were compared in healthy normal-weight young adult men. We hypothesise that all four proteins will elicit stronger satiety and plasma amino acid responses compared with the maltodextrin carbohydrate control, with "slow" proteins being more satiating and having a more delayed plasma amino acid response, than "fast" proteins.
Interventions
The design of the study is a randomised single-blind cross-over design. Each male participant participated in 5 sessions in total with a minimum of at least 2 days between each session. On each study day, participants arrived in the morning after fasting for about 10 hours. Upon arrival at the laboratory (Human Nutrition Research Unit), an intravenous cannula was placed in a vein of the subject's arm to allow for drawing of multiple blood samples. After the initial fasting blood draw (baseline),
The design of the study is a randomised single-blind cross-over design. Each male participant participated in 5 sessions in total with a minimum of at least 2 days between each session. On each study day, participants arrived in the morning after fasting for about 10 hours. Upon arrival at the laboratory (Human Nutrition Research Unit), an intravenous cannula was placed in a vein of the subject's arm to allow for drawing of multiple blood samples. After the initial fasting blood draw (baseline), the subject filled out his first set of Visual Analogue Scales (VAS) questionnaire to assess his feelings of appetite and well-being. The subject was given his preload meal (enriched tomato soup, plain biscuits and 100 ml of water) to consume within 15 min. Consumption of the preload meal was directly supervised, namely the amount of the preload meal ingested and the time it took to consume all of the preload meal were recorded. After complete ingestion of the preload meal (time 0), a questionnaire for the palatability of the preload meal and a VAS questionnaire is completed. The VAS questionnaire was completed at 30, 60, 90, 120, 150, 180, 240, 300, and 360 min. Blood (10 ml each) was collected at 60, 120, 180, 240, 300, and 360 min. At 120 and 240 min, 250 ml of water was given to the participants to keep them hydrated. After completing the 360 min blood draw and VAS questionnaire, the cannula was removed and subjects were provided with a hot meal and water to consume until satisfied within 15 min. The participant was asked to fill in a questionnaire asking about the overall likeability of the hot meal of fried rice at that time, and a VAS questionnaire 15 and 30 min following complete consumption of the hot meal. The participant was then able to leave the laboratory. The time involvement for each subject on each study day was at least 7 hours (420 min) and there are 5 study days, therefore 35 hours. The preload test meals consisted of 450 ml of one of the five tomato soups, 150 g of protein-free plain biscuits, and 100 ml of water. 400 ml of tomato soups were reconstituted in hot water (57 g/L) and cooled down before adding either 49 g of maltodextrin, a carbohydrate with a simple structure, or 48.9 g of whey protein isolate, or 48.6 g of alpha-lactabumin, a constituent of whey protein, or 54.4 g of casein, or 49.1 g of zein, a protein derived from maize. All the ingredients in the preload drinks are natural food-grade materials normally consumed in foods. The four protein preload test meals were balanced to provide 45 g of crude protein on a dry matter basis, and 45 g of available carbohydrate on a dry matter basis was provided in the maltodextrin carbohydrate preload test meal.
Sponsors
Riddet Institute, Massey University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
Male
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Men aged 18-40 years, within a body mass index (BMI) of 18-26 kg/m2 and in good general health.
Exclusion criteria
Exclusion criteria included smoking or recreational drug user, consumption of more than 2 standard units of alcohol per day, athletic training of more than 7 h per week, anaemic or a bleeding or clotting disorder or blood borne disease and/or taking medication that may affect blood clotting, a gastrointestinal disorder and/or diet-related illness, on a body weight loss or gain programme and/or have or being treated for any eating disorders, skip meals or having restrained eating habits, taking medication or supplements that may affect body weight, appetite, or gut function, vegetarian/vegan, an aversion to having blood samples taken. Participants who had an intolerance or disliking regarding the test foods, particularly milk, milk-derivatives, maize-derived products or proteins, were not included in the study.
Outcome results
None listed