Satiating effect of proteins in healthy subjects: a comparison of egg albumin, casein, gelatin, soy protein, pea protein, and wheat gluten.

The influence of six dietary protein types (egg albumin, casein, gelatin, soy protein, pea protein, and wheat gluten) on satiety and food intake was investigated. Twelve healthy subjects ingested six protein-manipulated lunches (approximately 5.2 MJ, 22% of energy as protein) according to a within-subjects design. Test meals were controlled for energy, macronutrients, fiber, and palatability. Nearly 65% of total protein varied between sessions. After lunch, satiety was assessed for 8 h and energy and macronutrients intakes were measured for 24 h. Blood was collected for determination of postprandial plasma glucose and insulin responses. Results showed no effect of the type of protein on satiety, on 24-h energy or macronutrient intakes, or on postprandial plasma glucose and insulin concentrations. These findings differ in part from those obtained previously in humans, which suggested that proteins may be differentiated in terms of their satiating capacities. We conclude that varying the protein source in a mixed meal does not affect food behavior in healthy humans, probably because coingestion of carbohydrate and fat with protein buffers the kinetics of the physiologic mechanisms implicated in postprandial satiety after a protein load.

Application of "Concept Mapping" in obese subjects: a pilot study in normo and underreporters.

BACKGROUND: One important step in nutritional education consists in identifying the patient prior knowledge in order to better educate him. The objectives of this pilot study, on twelve obese patients (6 underreporting patients - UR - and 6 normoreporting patients - NR) were to point out advantages and limits of a method: "concept mapping", a graphic representation of the nature and organization of knowledge, and to show eventual cognitive differences between the two groups of patients. METHODS: Concept maps were drawed during interviews and analysed, considering the concepts, the links between them, their regrouping in knowledge fields. Conceps maps of UR and NR patients were compared. RESULTS: Our results confirm the advantages of concept mapping as the mean to explore the cognitive representation of patients. Some differences between UR and NR patients were readable on the maps: UR patients are more sensitive to the difficulties of the diet than the NR patients. UR patients tend to express more frequently their feelings or personal experiences, and to be more easily invaded by their feelings (more numerous links of personal expressions at UR patients). CONCLUSION: Concept mapping brings new information on knowledge of obese patients. They appear important to better know the cognitive representations of underreporting patients. With such information, it would be easier for healthcare providers to adapt educational programs to the patients' understanding, taking into account their misconceptions, errors and lacks of learning.

Varying the protein source in mixed meal modifies glucose, insulin and glucagon kinetics in healthy men, has weak effects on subjective satiety and fails to affect food intake.

OBJECTIVE: To evaluate the influence of three dietary protein types (casein, gelatin, soy protein) on satiety and food intake, at two levels of loading (total energy of test meals: 3.6 or 1.8 MJ). DESIGN: The study employed a repeated measures design. Test meals were controlled for energy, macronutrients, fiber and palatability, and contained about 23% energy as protein (of which about 65% was experimentally manipulated). Postprandial subjective satiety and hunger, plasma glucose, insulin and glucagon were assessed for 8 h, and energy and macronutrient intakes were monitored for 24 h. SUBJECTS: Nine healthy normal-weight men. RESULTS: No effect of the type of protein on 24 h energy and macronutrient intakes was observed despite a significant effect of protein source on the kinetics of peripheral metabolic responses (but only after 3.6 MJ lunches), and inconsistent effects on subjective hunger and satiety responses A casein-enriched lunch delayed glucose and insulin responses for 1.5 h, compared with soy protein, probably due to a lag in gastric emptying. CONCLUSION: Varying the protein source in a mixed meal modifies glucose, insulin and glucagon kinetics in healthy men, but these variations in satiety-implicated factors have inconsistent effects on subjective satiety and fail to affect food intake. SPONSORSHIP: Eridania Béghin-Say, Vilvoorde, Belgium and Association Nationale de la Recherche Technique, France (Convention CIFRE no 537/94).

Snacking patterns in obese French women.

Snacking patterns were studied in 273 obese women by dietary history. Snacking was observed in 60% of the sample and occurred mainly during the afternoon. Total daily energy intake was higher in snackers than in non-snackers because of greater consumption of food at meals and between meals. A variety of foods were consumed as snacks (mean macronutrient content of snacks: 52% carbohydrate (CHO), 37% lipid and 12% proteins). CHO-rich protein-free snacks were a minority (20%). Only 7% of subjects were CHO-rich protein-free snackers. The eating pattern described by Wurtman in "carbohydrate cravers" was reported by less than 10% of these women. We conclude that, in Paris, snacking plays an important role in increasing energy consumption in obese women but macronutrient-specific snacking is not frequent.