Glycaemic and satiating properties of potato products.
OBJECTIVE
To investigate glycaemic and satiating properties of potato products in healthy subjects using energy-equivalent or carbohydrate-equivalent test meals, respectively.


METHODS
Thirteen healthy subjects volunteered for the first study, and 14 for the second. The tests were performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. EXPERIMENTAL DESIGN AND TEST MEALS: All meals were served as breakfast in random order after an overnight fast. Study 1 included four energy-equivalent (1000 kJ) meals of boiled potatoes, french fries, or mashed potatoes; the latter varying in portion size by use of different amounts of water. The available carbohydrate content varied between 32.5 and 50.3 g/portion. Capillary blood samples were collected during 240 min for analysis of glucose, and satiety was measured with a subjective rating scale. Study 2 included four carbohydrate-equivalent meals (50 g available carbohydrates) of french fries, boiled potatoes served with and without addition of oil, and white wheat bread (reference). The energy content varied between 963 and 1534 kJ/portion. Capillary blood samples were collected during 180 min for analysis of glucose, and satiety was measured using a subjective rating scale.


RESULTS
Study 1: boiled potatoes induced higher subjective satiety than french fries when compared on an energy-equivalent basis. The french fries elicited the lowest early glycaemic response and was less satiating in the early postprandial phase (area under the curve (AUC) 0-45 min). No differences were found in glycaemic or satiety response between boiled or mashed potatoes. Study 2: french fries resulted in a significantly lower glycaemic response (glycaemic index (GI)=77) than boiled potatoes either with or without addition of oil (GI=131 and 111, respectively). No differences were found in subjective satiety response between the products served on carbohydrate equivalence.


CONCLUSIONS
Boiled potatoes were more satiating than french fries on an energy-equivalent basis, the effect being most prominent in the early postprandial phase, whereas no difference in satiety could be seen on a carbohydrate-equivalent basis. The lowered GI for french fries, showing a typical prolonged low-GI profile, could not be explained by the fat content per se.
Leeman
M
M
Applied Nutrition and Food Chemistry, Department of Food Technology, Engineering and Nutrition, Lund University, Lund, Sweden.
Ostman
E
E
Björck
I
I
D000328:Adult; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D003296:Cooking / Q000379:methods; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000493:pharmacokinetics*; D004041:Dietary Fats / Q000494:pharmacology; D002149:Energy Intake / Q000502:physiology; D005260:Female; D038321:Glycemic Index; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D019518:Postprandial Period; D012528:Satiety Response / Q000502:physiology*; D011198:Solanum tuberosum / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats