The NHS took issue with the study’s cross-sectional design. It said that because the study was designed this way, it can only provide “a snapshot” of the possible impact of different weaning methods on children’s food preferences, BMI and other health outcomes—but the study can’t come to solid conclusions about these.
“It cannot show, for example, that babies who prefer carbohydrates do so because they were weaned on finger foods, as some news sources have reported,” the NHS pointed out. “Many factors can affect a child’s food preferences and BMI, including genetic factors, exercise and social and demographic background.”
The NHS pointed out that, “A more reliable method of finding out if baby-led weaning did result to healthier food choices and weight would be a randomized controlled trial in which parents were randomly allocated one of the two weaning methods to use, and their babies followed over a period of time to see whether weaning method led to differences in dietary preference or BMI.”
But since such as trial may have ethical and feasibility issues, an alternative would be to conduct a study that follows babies weaned by the two methods over a longer period.
This “would be preferable to a cross-sectional study, which only looks at weaning methods, children’s food preferences and other factors at one point in time,” the NHS pointed out.
Another weakness of the study was that weaning methods were self-reported or reported by parents, NHS said.
Small sample size
While the study found differences in the BMI of the babies, the NHS pointed out that the small sample size makes it difficult to draw reliable comparisons between the spoon-fed babies and babies who were allowed to eat finger foods by themselves.
“For example, although eight babies were obese in the spoon-fed group and none in the baby-led group, this finding could be due to chance,” the health provider said.
What’s worse, when overweight and obese babies were combined, 10 babies in the spoon-fed and nine in the baby-led groups were overweight or obese. “This raises the strong possibility that there would be no real difference in BMI if a much larger group of babies were looked at,” the NHS concluded.
How the research was done
Anxious mom and want to find out for yourself? Here’s how the research was done and its main findings:
Between June 2006 and January 2009, the Nottingham University researchers recruited parents of 155 babies between 20-78 months. The parents that fell into the “spoon-feeding” group were recruited from the researchers’ own laboratory database, while the parents that were put into the “baby-led weaning” group were recruited by advertising on the Internet.
All the parents were asked to complete a standard questionnaire that asked about their infants:
• height and weight
• feeding and weaning style
• preferences for 151 foods (rated from 1 “loves it” to 5 “hates it”)
• frequency of consuming particular foods (with ratings from 1 “more than once a day” to 7 “less than once a month”
• pickiness—parents were asked to classify their child as picky eaters or not.
Then, the babies’ preferences were analyzed by standard food categories — carbohydrates, proteins and dairy, including a category for whole meals like lasagna. The parents’ socioeconomic status was also assessed using validated measures.
Currently, there’s no formal definition of weaning, so researchers used the parents’ own reports of weaning styles to divide parents into two groups. They also questioned some parents about weaning in more detail, to verify these self-reported methods.
As the baby-led weaning group tended to be younger than the spoon-fed group, the researchers carried out their analyses on food preferences and weaning method using a sub-sample of 74 infants—37 from the spoon-fed group matched by age to 37 from the baby-led weaning group. For all other analyses, they used the whole sample.
What were the raw findings?
• The baby-led weaning group liked carbohydrates best.
• The spoon-fed group liked sweet foods most.
• Preference and frequency of consumption were not influenced by socioeconomic status, although an increased liking for vegetables was associated with a higher social class.
• Using NHS BMI guidelines, eight babies in the spoon-fed group were classified as obese (12.7percent), while none in the baby-led group fell into that category.
• Nine babies in the baby-led weaning group (14.3 percent) were overweight compared to two in the spoon-fed group (3.2 percent).
• Three babies in the baby-led weaning group were classed as underweight (4.7 percent) compared to none in the spoon-fed group.
• No difference in picky eating was found between the two groups.
Overall, the study proves very little about the possible impact of different weaning methods on children’s food preferences, BMI or other health outcomes, NHS concludes.