Second-meal Effect Research Articles

Utilizing the Second-Meal Effect in Type 2 Diabetes: Practical Use of a Soya-Yogurt Snack

OBJECTIVETo evaluate the effect of a prebreakfast high-protein snack upon postbreakfast hyperglycemia.RESEARCH DESIGN AND METHODSWe studied 10 men and women with diet- and/or metformin-controlled type 2 diabetes. Metabolic changes after breakfast were compared between 2 days: breakfast taken only and soya-yogurt snack taken prior to breakfast.RESULTSThere was a significant lower rise in plasma glucose on the snack day. The incremental area under the glucose curve was 450 ± 55 mmol · min/l on the snack day compared with 699 ± 99 mmol · min/l on the control day (P = 0.013). The concentration of plasma free fatty acids immediately before breakfast correlated with the increment in plasma glucose (r = 0.50, P = 0.013).CONCLUSIONSConsuming a high-protein prebreakfast snack results in almost 40% reduction of postprandial glucose increment. The second-meal effect can be applied simply and practically to improve postbreakfast hyperglycemia in people with type 2 diabetes.

The second-meal phenomenon is associated with enhanced muscle glycogen storage in humans

The rise in blood glucose after lunch is less if breakfast has been eaten. The metabolic basis of this second-meal phenomenon remains uncertain. We hypothesized that storage of ingested glucose as glycogen could be responsible during the post-meal suppression of plasma NEFAs (non-esterified fatty acids; 'free' fatty acids). In the present study we determined the metabolic basis of the second-meal phenomenon. Healthy subjects were studied on two separate days, with breakfast and without breakfast in a random order. We studied metabolic changes after a standardized test lunch labelled with 3 g of 13C-labelled (99%) glucose. Changes in post-prandial muscle glycogen storage were measured using 13C magnetic resonance spectroscopy. The rise in plasma glucose after lunch was significantly less if breakfast had been taken (0.9+/-0.3 compared with 3.2+/-0.3 mmol/l, with and without breakfast respectively; P<0.001), despite comparable insulin responses. Pre-lunch NEFAs were suppressed after breakfast (0.13+/-0.03 compared with 0.51+/-0.04 mmol/l) and levels correlated positively with the maximum glucose rise after lunch (r=0.62, P=0.001). The increase in muscle glycogen signal was greater 5 h after lunch on the breakfast day (103+/-21 compared with 48+/-12 units; P<0.007) and correlated negatively with plasma NEFA concentrations before lunch (r=-0.48, P<0.05). The second-meal effect is associated with priming of muscle glycogen synthesis consequent upon sustained suppression of plasma NEFA concentrations.

The Second-Meal Phenomenon in Type 2 Diabetes

OBJECTIVEIn health, the rise in glucose after lunch is less if breakfast is eaten. We evaluated the second-meal effect in type 2 diabetes.RESEARCH DESIGN AND METHODSMetabolic changes after lunch in eight obese type 2 diabetic subjects were compared on 3 days: breakfast eaten, no breakfast, and no breakfast but intravenous arginine 1 h before lunch.RESULTSDespite comparable insulin levels, the rise in plasma glucose after lunch was considerably less if breakfast had been eaten (0.68 ± 1.49 vs. 12.32 ± 1.73 vs. 7.88 ± 1.03 mmol · h−1 · l−1; P < 0.0001). Arginine administration almost halved the lunch rise in plasma glucose (12.32 ± 1.73 vs. 7.88 ± 1.03 mmol · h−1 · l−1). The plasma free fatty acid concentration at lunchtime directly related to plasma glucose rise after lunch (r = 0.67, P = 0.0005).CONCLUSIONSThe second-meal effect is preserved in type 2 diabetes. Premeal administration of a nonglucose insulin secretagogue results in halving the postprandial glucose rise and has therapeutic potential.

Effect of cereal test breakfasts differing in glycemic index and content of indigestible carbohydrates on daylong glucose tolerance in healthy subjects

Background: Frequent hyperglycemic episodes are increasingly being associated with an increased risk of type 2 diabetes and cardiovascular disease.Objective: We studied the extent to which acute glycemia and glycemia after subsequent meals can be modulated by the characteristics of cereal foods, such as glycemic index (GI) and content of indigestible carbohydrates.Design: Twelve healthy subjects consumed test meals in a random order. In series 1, the test meals were consumed at breakfast, and postprandial blood glucose incremental areas under the curve (IAUCs) were calculated after the test breakfast, standardized lunch, and standardized dinner. In series 2, the subjects consumed test evening meals and IAUCs were calculated after a subsequent standardized breakfast. Breath hydrogen was measured as an indicator of colonic fermentation.Results: Barley or rye kernel breakfasts lowered the blood glucose IAUC (0–120 min) at breakfast, at a subsequent lunch, and the cumulative IAUCs (breakfast+lunch+dinner) when compared with white-wheat bread (P < 0.05). The lunch blood glucose IAUCs were positively correlated with breakfast IAUCs (r = 0.30, P < 0.05). Breath hydrogen excretion was negatively correlated with blood glucose IAUCs after lunch (r = −0.33, P < 0.05) and dinner (r = −0.22, P < 0.05). A barley kernel evening meal resulted in lower IAUCs (P < 0.05) and higher breath hydrogen (P < 0.001) after a subsequent breakfast compared with white-wheat bread.Conclusions: Glucose tolerance at subsequent meals can be notably improved during the course of a whole day or overnight by choosing specific low-GI, whole-grain cereal products. A low GI may be sufficient to achieve a second-meal effect from breakfast to lunch. A specific indigestible carbohydrate mixture appears to be required to show benefits on glucose tolerance in a longer time frame (9.5 h), most likely mediated through colonic fermentation.

Influence of the glycaemic index of an evening meal on substrate oxidation following breakfast and during exercise the next day in healthy women

To investigate whether the 'overnight second-meal effect' results in altered substrate oxidation during the postprandial period following breakfast and subsequent sub-maximal exercise in women. Seven recreationally active women were recruited for the study. In each trial, participants were provided with their evening meal on day 1, which was composed of either high glycaemic index (HGI) or low glycaemic index (LGI) carbohydrates (CHO). On day 2, participants were provided with a standard HGI breakfast and then performed a 60 min run at 65% \[V.]O(2 max) 3 h later. The incremental area under the curve (IAUC) for plasma glucose concentrations during the postprandial period following breakfast was greater in the HGI trial compared to the LGI trial (P<0.01). Similarly, the IAUC for serum insulin concentrations was greater in the HGI trial than the LGI trial (P<0.05). No differences in plasma free-fatty acids (FFA) or plasma glycerol concentrations were found between trials during the postprandial period. During subsequent exercise, there were no significant differences in substrate metabolism. The glycaemic index of an evening meal does not alter substrate oxidation at rest following breakfast or during subsequent submaximal exercise in women. This study provides further evidence for the overnight second-meal effect on glycaemic responses following a LGI mixed evening meal.

Effects of a palatinose-based liquid diet (Inslow) on glycemic control and the second-meal effect in healthy men

Postprandial hyperglycemia induces prolonged hyperinsulinemia, which is a risk factor for type 2 diabetes mellitus. Foods with a low glycemic index blunt the rapid rise in postprandial plasma glucose and insulin levels. We herein investigated the effects of a novel, palatinose-based liquid diet (Inslow, Meiji Dairy Products, Tokyo, Japan) on postprandial plasma glucose and insulin levels and on the rate of substrate oxidation in 7 healthy men. Furthermore, to examine the effects of Inslow on the second-meal effect, we quantified our subjects' postprandial plasma glucose, insulin, and free fatty acid levels for up to 7 hours after they ingested a breakfast containing Inslow or control formula, followed by a standard lunch 5 hours later. Our results showed that peak plasma glucose and insulin levels 30 minutes after Inslow loading were lower than after control formula loading. Postprandial fat oxidation rates in the Inslow group were higher than in the control formula group ( P < .05). In the second-meal effect study, plasma glucose and insulin levels after lunch in the Inslow group were lower than in the control formula group ( P < .01), although the peak levels in these groups were not different. The free fatty acid concentration in the Inslow group immediately before lunch was significantly lower than in the control formula group ( P < .05). In conclusion, consumption of Inslow at breakfast appears to improve patient glycemic control by reducing their postprandial plasma glucose and insulin levels after lunch (second-meal effect).

Psyllium fiber reduces rise in postprandial glucose and insulin concentrations in patients with non-insulin-dependent diabetes

The ability of psyllium fiber to reduce postprandial serum glucose and insulin concentrations was studied in 18 non-insulin-dependent diabetic patients in a crossover design. Psyllium fiber or placebo was administered twice during each 15-h crossover phase, immediately before breakfast and dinner. No psyllium fiber or placebo was given at lunch, which allowed measurement of residual or second-meal effects. For meals eaten immediately after psyllium ingestion, maximum postprandial glucose elevation was reduced by 14% at breakfast and 20% at dinner relative to placebo. Postprandial serum insulin concentrations measured after breakfast were reduced by 12% relative to placebo. Second-meal effects after lunch showed a 31% reduction in postprandial glucose elevation relative to placebo. No significant differences in effects were noted between patients whose diabetes was controlled by diet alone and those whose diabetes was controlled by oral hypoglycemic drugs. Results indicate that psyllium as a meal supplement reduces proximate and second-meal postprandial glucose and insulin concentrations in non-insulin-dependent diabetics.

Second-meal effect: low-glycemic-index foods eaten at dinner improve subsequent breakfast glycemic response

The effects of the glycemic index (GI) of carbohydrate eaten the previous night on the glycemic response to a standard test meal eaten subsequently in the morning (breakfast) was studied. On separate evenings normal subjects ate low- or high-GI test meals of the same nutrient composition. The dinners consisted of single foods in two experiments and mixed meals containing several foods in the third. The differences between the observed glycemic responses to low- and high-GI dinners were predicted by their GIs. The glycemic responses to breakfast were significantly lower on mornings after low-GI dinners than after high-GI dinners. Eating, at dinner, foods with different fiber contents but the same GI had no effect on postbreakfast glycemia. We conclude that the GI predicts the difference between glycemic responses of mixed dinner meals; breakfast carbohydrate tolerance is improved when low-GI foods are eaten the previous evening.