Context: Early dietary habits play a crucial role in shaping long-term health outcomes. Understanding the effects of different carbohydrate types on physiological markers is essential for developing evidence-based nutritional guidelines for toddlers. Objective: The aim was to systematically evaluate the impact of both digestible and nondigestible carbohydrate intake during early childhood (1–4 years of age) on various health outcomes, including growth patterns, metabolic parameters, and the development of risk of cardiovascular diseases. Data Sources: PubMed, Embase, and CENTRAL databases were searched up to April 2022 to identify studies investigating carbohydrate consumption in toddlers. Data Extraction: The types of carbohydrates consumed, their sources, and their associations with growth parameters and metabolic markers were extracted. Thirty-one publications, including 18 cohort studies and 2 randomized controlled trials, were included. Data Analysis: The risk of bias was assessed using the Mixed Methods Appraisal Tool. A narrative synthesis was performed, with a visual summary table of the direction of effects. Conclusion: In toddlers, the negative impact on health risks later in life is more pronounced for digestible dietary carbohydrate intake in liquid forms, such as sugar-sweetened beverages and fruit juice, compared with solid forms. Higher nondigestible carbohydrate (dietary fiber) intake during early childhood showed a beneficial trend on later lipid profile. Further studies are required to comprehensively assess the effect of digestible and nondigestible carbohydrate intake in toddlers on cognitive and psychomotor development, infections, bowel function, and gut microbiota.

The nutritional environment during fetal and early postnatal life has a long-term impact on growth, development, and metabolic health of the offspring, a process termed “nutritional programming.” Rodent models studying programming effects of nutritional interventions use either purified or grain-based rodent diets as background diets. However, the impact of these diets on phenotypic outcomes in these models has not been comprehensively investigated. We used a previously validated (C57BL/6J) mouse model to investigate the effects of infant milk formula (IMF) interventions on nutritional programming. Specifically, we investigated the effects of maternal diet type (i.e., grain-based vs purified) during early lactation and prior to the intervention on offspring growth, metabolic phenotype, and gut microbiota profile. Maternal exposure to purified diet led to an increased post-weaning growth velocity in the offspring and reduced adult diet-induced obesity. Further, maternal exposure to purified diet reduced the offspring gut microbiota diversity and modified its composition post-weaning. These data not only reinforce the notion that maternal nutrition significantly influences the programming of offspring vulnerability to an obesogenic diet in adulthood but emphasizes the importance of careful selection of standard background diet type when designing any preclinical study with (early life) nutritional interventions.

Background: Lactose, a disaccharide of glucose and galactose, is the primary carbohydrate found in milk. Recently, there has been an increased demand for low lactose/lactose-free infant formulas. Maltodextrin (MDX) is a popular, alternative carbohydrate source in these formulas, yet the (long-term) health effects of consuming maltodextrin in early life are unclear. Previously, consuming galactose (partly replacing glucose) in a postweaning diet was shown to improve metabolic health in mice. Objective: To investigate the effects of partly replacing MDX with galactose in post-weaning diets on body composition and energy metabolism. Methods: Weaned, individually housed female C57BL/6JRccHsd mice received isocaloric diets (in a dough ball format) with different carbohydrate profiles for three weeks (postnatal day (PN)21-PN42). GLUGAL (lactose mimic, n = 13) contained 15.7 en% glucose, 15.7 en% galactose and 14.9 en% MDX, and GAL (n = 12) contained 15.7 en% galactose, no glucose and 30.6 en% MDX. MDX (n = 13) contained 38.4 en% MDX and 7.9 en% glucose. Energy metabolism was assessed via indirect calorimetry from PN40-PN42. At PN42, all mice were challenged with a 40 en% high-fat diet (HFD) until PN105. Body composition was measured weekly using Echo-MRI. At PN105, fasted (4 h) mice were sacrificed for serum and tissue analysis. Results: At PN42, mice in both galactose-fed groups (GLUGAL and GAL) had a significantly lower body weight, fat mass and relative fat mass compared with the MDX group (p < 0.0001). The respiratory exchange ratio was significantly lower in both galactose-fed groups compared with the MDX group (p < 0.05), suggesting lower carbohydrate oxidation and thus higher relative fat oxidation levels. In parallel, both galactose-fed groups showed lower energy expenditure (p < 0.05). Discussion: The GAL mice were similar to the GLUGAL (lactose mimic) mice in terms of body weight, composition and energy metabolism, while being significantly different from the MDX group at PN42. These findings suggest an improvement of body composition and energy metabolism when replacing MDX with galactose. This study is the first to compare the effects of replacing part of MDX with galactose in early life and reinforces the impact of the type of carbohydrates on metabolic outcomes.