Study protocol: optimized complementary feeding study (OTIS): a randomized controlled trial of the impact of a protein-reduced complementary diet based on Nordic foods.
BACKGROUND
What we eat as infants and children carries long-term consequences. Apart from breastfeeding, the composition of the complementary diet, i.e. the foods given to the infant during the transition from breast milk/infant formula to regular family foods affects the child's future health. A high intake of protein, a low intake of fruits, vegetables and fish and an unfavorable distribution between polyunsaturated and saturated fats are considered to be associate with health risks, e.g. obesity, type 2 diabetes and dyslipidemia later in life.


METHODS
In a randomized, controlled study from 6 to 18 months of age we will compare the currently recommended, Swedish complementary diet to one based on Nordic foods, i.e. an increased intake of fruits, berries, vegetables, tubers, whole-grain and game, and a lower intake of sweets, dairy, meat and poultry, with lower protein content (30% decrease), a higher intake of vegetable fats and fish and a systematic introduction of fruits and greens. The main outcomes are body composition (fat and fat-free mass measured with deuterium), metabolic and inflammatory biomarkers (associated with the amount of body fat) in blood and urine, gut microbiota (thought to be the link between early diet, metabolism and diseases such as obesity and insulin resistance) and blood pressure. We will also measure the participants' energy and nutrient intake, eating behavior and temperament through validated questionnaires, acceptance of new and unfamiliar foods through video-taped test meals and assessment of cognitive development, which we believe can be influenced through an increased intake of fish and milk fats, notably milk fat globule membranes (MFGM).


DISCUSSION
If the results are what we expect, i.e. improved body composition and a less obesogenic, diabetogenic and inflammatory metabolism and gut microbiota composition, a more sustainable nutrient intake for future health and an increased acceptance of healthy foods, they will have a profound impact on the dietary recommendations to infants in Sweden and elsewhere, their eating habits later in life and subsequently their long-term health.


TRIAL REGISTRATION
NCT02634749 . Registration date 18 December 2015.
['Lind|Torbjörn|T|http://orcid.org/0000-0001-6328-1098', 'Johansson|Ulrica|U|', 'Öhlund|Inger|I|', 'Lindberg|Lene|L|', 'Lönnerdal|Bo|B|', 'Tennefors|Catharina|C|', 'Hernell|Olle|O|']
D018753:Diet, Protein-Restricted D005260:Female D005500:Follow-Up Studies D006801:Humans D007223:Infant D007225:Infant Food D000068104:Infant Health D007227:Infant Nutritional Physiological Phenomena D008297:Male D013548:Sweden
Obesity Body composition Microbiota Insulin resistance Child development Child nutrition physiology Feeding behavior Food preference Growth Hypertension Infant food