No abstract

In subjects with untreated type 2 diabetes, we previously determined that a weight-maintenance, non-ketogenic diet containing 30 % protein, 50 % fat and 20 % carbohydrate (30:50:20) decreased the percentage total glycohaemoglobin (%tGHb) by 2·2 % glycohaemoglobin over 5 weeks compared to a diet recommended for the American public (protein -fat -carbohydrate 15:30:55). Both the fasting and postprandial glucose were decreased. The objective of the present study was to determine if increasing the carbohydrate content from 20 to 30 % at the expense of fat would still provide a similar effect on %tGHb, fasting and postprandial glucose concentration. Eight men with untreated type 2 diabetes were studied over a 5-week period. Results at the beginning (standard diet) and end of the 5-week study were analysed. Body weight was stable. Fasting glucose concentration decreased by 40 %; 24 h glucose area response decreased by 45 %. Insulin did not change. Mean %tGHb decreased by 1·7 (from 10·8 to 9·1 %), and was still decreasing linearly at 5 weeks. In conclusion, a high-protein, 30 % carbohydrate diet could be a patient-empowering method of improving the hyperglycaemia of type 2 diabetes without pharmacologic intervention. Long-term effects and general applicability of this diet remain to be determined. High-protein diet: Glycaemic index: Glycohaemoglobin: InsulinWe have reported previously that in a randomized, crossover designed study in people with untreated type 2 diabetes, a diet in which the carbohydrate content was reduced from 55 to 40 % of food energy with a corresponding increase in protein from 15 to 30 %, and without a change in fat content, resulted in a decrease in percentage total glycohaemoglobin (%tGHb) of 0·8 at the end of the 5-week study 1 . Body weight was unchanged. The major effect on plasma glucose concentration was a reduction in the postprandial glucose excursions. The fasting glucose value was little changed.Subsequently, we determined the effect on the circulating glucose concentration and %tGHb of a diet in which the protein content remained at 30 % of food energy. However, the carbohydrate content was decreased to 20 % and the fat content was increased to 50 % of food energy. After 5 weeks on this diet the %tGHb had decreased by 2·2 (from 9·8 to 7·6 %) 2 . The 24 h glucose profile indicated not only a decrease in postprandial glucose excursions but also a decrease in the fasting glucose concentration. Indeed, the reduced 24 h glucose profile was approaching that in people without diabetes. Again, body weight did not decrease when compared to the standard diet (15 % protein, 30 % fat, 55 % carbohydrate).Based on the above information we now have designed a diet containing the same high-protein content but with an increase in carbohydrate content from 20 to 30 % of food energy and with a corresponding decrease in fat content from 50 to 40 %. The objective was to determine if this increase in carbohydrate content would still result in a significant decrease in fasting glucose and a decrease in %tG...

In summary, phenylalanine in an amount moderately greater than that in a large protein meal stimulates an increase in insulin and glucagon concentration. It markedly attenuates the glucose-induced rise in plasma glucose when ingested with glucose.

Background: Ingested proteins are known to stimulate a rise in insulin and glucagon concentrations. In our effort to explain this effect, we have begun to measure the effect of individual amino acids. Objectives: The objectives were to determine the effect of lysine ingestion on insulin and glucagon concentrations and whether the effect is moderated by glucose ingestion. Design: Thirteen healthy subjects were studied on 4 occasions. Water, 25 g glucose, 1 mmol lysine/kg lean body mass, or lysine plus glucose was given on separate occasions at 0800 after a 12-h fast. Serum lysine, glucose, insulin, and glucagon were measured during a 2.5-h period. The amount of lysine provided was equivalent to that present in a 672-g (24-oz) steak. Results: Lysine ingestion resulted in an '3-fold increase in lysine concentration and in a small decrease in glucose concentration. When lysine was ingested with glucose, the 2.5-h glucose area response decreased by 44% (P , 0.02). Lysine alone increased the insulin area response modestly; the insulin increase when lysine was ingested with glucose was similar to that when only glucose was ingested. Lysine stimulated an increase in glucagon (P , 0.02), whereas glucose decreased glucagon. Conclusions: Lysine ingestion results in a small decrease in serum glucose and an increase in glucagon and insulin concentrations. Lysine ingested with glucose dramatically attenuated the glucosestimulated glucose response, but there was no change in insulin response. Whether similar effects will be observed with more physiologic doses of lysine remains to be determined. 2009;90:314-20. Am J Clin Nutr

No abstract