Decaffeinated coffee improves insulin sensitivity in healthy men.

Epidemiological studies have found coffee consumption is associated with a lower risk for type 2 diabetes mellitus, but the underlying mechanisms remain unclear. Thus, the aim of this randomised, cross-over single-blind study was to investigate the effects of regular coffee, regular coffee with sugar and decaffeinated coffee consumption on glucose metabolism and incretin hormones. Seventeen healthy men participated in five trials each, during which they consumed coffee (decaffeinated, regular (containing caffeine) or regular with sugar) or water (with or without sugar). After 1 h of each intervention, they received an oral glucose tolerance test with one intravenous dose of [1-13C]glucose. The Oral Dose Intravenous Label Experiment was applied and glucose and insulin levels were interpreted using a stable isotope two-compartment minimal model. A mixed-model procedure (PROC MIXED), with subject as random effect and time as repeated measure, was used to compare the effects of the beverages on glucose metabolism and incretin parameters (glucose-dependent insulinotropic peptide (GIP)) and glucagon-like peptide-1 (GLP-1)). Insulin sensitivity was higher with decaffeinated coffee than with water (P<0·05). Regular coffee with sugar did not significantly affect glucose, insulin, C-peptide and incretin hormones, compared with water with sugar. Glucose, insulin, C-peptide, GLP-1 and GIP levels were not statistically different after regular and decaffeinated coffee compared with water. Our findings demonstrated that the consumption of decaffeinated coffee improves insulin sensitivity without changing incretin hormones levels. There was no short-term adverse effect on glucose homoeostasis, after an oral glucose challenge, attributable to the consumption of regular coffee with sugar.

How much human milk do infants consume? Data from 12 countries using a standardized stable isotope methodology.

The WHO has developed new growth curves based on breast-fed infants. Recommendations for energy intake have been adopted based on measurements of total energy expenditure. Data on human milk (HM) intake are needed to estimate the energy intake from this food source. However, objective HM data from around the world have not been available, because these measurements are difficult to obtain. Stable isotope methods have been developed to provide objective measurements over a 14-d period. A pooled analysis of 1115 data points of HM intake, obtained using the dose to the mother deuterium oxide turnover method, was undertaken in infants aged 0-24 mo from 12 countries across 5 continents. A hierarchical model was needed to estimate mean HM intake and its variance within and between countries given the complexity of the data. The overall mean HM intake was 0.78 (95% CI = 0.72, 0.84) kg/d, and the age-specific estimates indicated that intake increased over the first 3-4 mo and remained above 0.80 kg/d until 6-7 mo. The variability of intake increased in late infancy. Boys consumed 0.05 kg/d more than girls (P < 0.01). HM intake was strongly, inversely associated with non-HM water intake [r = -0.448 (95% CI -0.511 to -0.385); P < 0.0001]. These objective isotope values of HM intake improve our understanding of the magnitude and variability of HM intake within and across populations and help to estimate nutrient intakes in breast-fed infants.