Background: Some infants experience excessive weight gain during exclusive breastfeeding. The cause is unknown, but variation in human milk composition might play a role. Several human milk koligosaccharides (HMOs) have been associated with growth velocity in breastfed infants, and it has been suggested that the mechanism could be through an effect on infant gut microbiota composition. Objective: The purpose of this exploratory study was to evaluate if HMO composition was different in milk fed to infants with excessive weight gain compared to infants with normal weight gain. Furthermore, we aimed to examine if HMO composition was associated with growth velocity and change in body composition and if there were maternal determinants of HMO composition. Materials and Methods: We recruited 13 high weight-gain (HW) and 17 normal weight-gain (NW) breastfed infants, collected human milk and anthropometry data at 5 and 9 months, and analyzed HMO composition by high performance liquid chromatography. Results: In the HW group eight out of 11 infants received milk from secretor mothers and in the NW group 15 out of 17. Comparing milk from Secretor mothers only, four HMO's were significantly different between the HW and NW group at 5 months and two remained significant at 9 months. Total HMO concentrations as well as total HMO-bound fucose at 5 months were positively associated with both fat mass index (FMI) and weight velocity from 0 to 5 months (all p < 0.025). 2′-fucosyllactose (2′-FL) was positively associated with weight velocity from 0 to 5 months and FMI at 5 months. In contrast, lacto-N-neotetraose was lower in the HW group ( p = 0.012) and negatively associated with height-for-age Z-scores ( p = 0.008), weight velocity from 0 to 5 months ( p = 0.009) and FMI ( p = 0.033). Maternal BMI at 5 months was negatively associated with 6′-sialyllactose and sialyl-lacto-N-tetraose (LSTb) and positively with 2′-FL, total HMO and total HMO-bound fucose (all p ≤ 0.03). Conclusion: In a small cohort, we found significantly different HMO concentrations in milk to exclusively breastfed infants with excessive weight gain, suggesting that some HMOs, including 2′-FL, which is the most abundant HMO and currently added to some infant formula, could be part of the cause for the excessive weight gain.

Objective: To compare dietary patterns and food and macronutrient intakes among adults in three ethnic groups in rural Kenya. Design: In the present cross-sectional study, dietary intake was estimated in adult volunteers using two non-consecutive interactive 24 h recalls. Dietary patterns were assessed from the number of meals and snacks per day and from the food items and major food groups registered, and their contribution to energy intake (EI) was calculated. Anthropometric values were measured and sociodemographic data obtained using a questionnaire. Setting: A cross-sectional study was conducted in the Bondo, Kitui and Transmara districts of rural Kenya. A high prevalence of food insecurity in Kenya underlines the importance of describing the dietary patterns and intakes in different Kenyan ethnic groups. Subjects: A total of 1163 (61 % women) adult Luo, Kamba and Maasai, with a mean age of 38?6 (range: 18-68) years, volunteered to participate. Results: Dietary patterns and food groups contributing to EI differed significantly among the ethnic groups. Mean EI ranged from 5?8 to 8?6 MJ/d among women and from 7?2 to 10?5 MJ/d among men, with carbohydrates contributing between 55?7 % and 74?2 % and fat contributing between 14?5 % and 30?2 % of total EI. Mean protein intake ranged from 0?72 to 1?3 g/kg per d, and EI:BMR ratio ranged between 1?1 and 1?6 in both sexes, and was highest among the Luo. Prevalence of underweight (BMI , 18?5 kg/m 2 ) was 13?7 %, 20?5 % and 24?2 % in the Luo, Kamba and Maasai, respectively. Conclusions: The degree of food insecurity measured as a degree of undernutrition and as dietary patterns differed considerably among the ethnic groups. The Maasai and Kamba in particular were exposed to food insecurity. Keywords Nutrition Population study Traditional food Rural populations KenyaKenya is one of several African countries facing food emergencies (1) . According to the FAO country profile on food security indicators, data from Kenya show that the proportion of food insecurity (determined as undernourishment with an average daily energy intake (EI) ,7?33 MJ/person) was 30 % during the period 2004-2006 (2) . Food insecurity exists when people lack secure access to sufficient amounts of safe and nutritious food for normal growth and development and an active and healthy life (3) . In the absence of direct measures of food insecurity, the nutritional status of individuals is often used as outcome measures to reflect the end result of all factors affecting the nutritional status, including food security. One of several indicators of food insecurity among adults is underweight (BMI , 18?5 kg/m 2 ). Recently, we showed a high prevalence of both underweight (17 % and 23 % in women and men) and overweight (BMI $ 25?0 kg/m 2 ; 26 % and 12 % in women and men, respectively) among rural Kenyans in a population group comprising Luo, Kamba and Maasai (4) . This clearly *Corresponding author: Email awh@niph.dk r The Authors 2011

Some infants experience excessive weight gain (EWG) during exclusive breastfeeding, but causes and consequences are unknown. The objective was to identify factors associated with early EWG. Infants with EWG (HW-group) were examined at 5, 9 and 18 mo and compared to a breastfed group with normal weight gain (NW-group). Anthropometry, body composition, milk and blood samples, and milk intake were measured. Mean body-mass-index-for-age z-scores (BAZ) increased 1.93 from birth to 5 mo in the HW-group (n = 13) while the NW-group (n = 17) was unchanged (−0.01). The HW-group had 70% more fat mass at 5 mo, and then showed marked catch-down in BAZ from 5 to 18 mo (−0.84). Milk intake at 5–6 mo did not differ between the groups. In the HW-group milk-leptin was lower at 5 mo and serum-leptin was considerably higher at 5 and 9 mo compared to the NW-group. Serum-leptin at 5 mo was positively associated with weight-for-age z-score (WAZ) and fat mass and negatively with WAZ change from 5 to 9 mo. In conclusion, breastfed infants with EWG had catch-down growth when other foods were introduced. Low milk-leptin in the HW-group may have stimulated appetite and milk intake when weight gain was high. High serum-leptin in the HW-group suggests early leptin resistance, which could impact cerebral regulation of energy intake. Larger studies are needed to confirm these results.