Babies weaned on pureed food tend to end up fatter than infants whose first tastes are finger food, researchers believe.
Spoon feeding babies mashed up fruits and vegetables appears to give them a sweeter tooth, a Nottingham University team found after studying 155 children.
Infants who are instead allowed to feed themselves solids tend to favour more satiating carbohydrates like toast.
This early self-regulation of what to eat keeps them slim, BMJ Open says.
The researchers found spoon-fed babies were more often obese, although, overall, most of the youngsters in both groups were a healthy weight.
This weight difference remained even after the investigators accounted for other factors that might have influenced the findings, such the baby's birth weight, how long they were breastfed for and whether their parents were rich or poor.
Dr Ellen Townsend, who led the research, believes baby-led weaning - where the child is offered a range of chunky foods to grab and self-feed - sets the stage for healthy eating in early childhood.
The ages of the 155 children who took part in the study ranged between 20 months and six years.
Questionnaires filled in by their parents revealed those children who were introduced early to finger foods developed a preference for carbohydrates like toasted pitta bread and pasta over sweeter foods like sugary fruit purees.
This was despite the fact that along with sweet foods, children in the spoon-fed group had also been offered carbohydrates, fruits and vegetables, proteins and whole meals such as lasagne more often than those in the baby-led weaning group.
Dr Townsend said: "It could be an age of introduction effect that we are seeing. Carbohydrates are ideal finger foods.
"But self-control of feeding may also be a factor. You are handing over control and letting the baby decide how much they want to eat.
"With spoon feeding there is the temptation to get into them whatever is left in the bowl or the jar."
She said longer-term studies were now needed to track the knock-on effect, if any, of weaning method on weight in adolescence and adulthood.
Rosie Dodds of the National Childbirth Trust said the findings suggested that it was safe to let babies feed themselves and choose their own foods when they were ready.
And Tam Fry, of the National Obesity Forum, said it was "quite logical" that babies might inherently know best when it came to which weaning foods to eat.
"It is important that they experience all five food groups and experiment with variety as much as possible.
"If half of it finishes on the floor, so be it - the value of experimentation in the early months of nutrition is incalculable, and babies won't willingly starve themselves.
"If this also has the advantage of reducing unhealthy weight gain and avoiding obesity, it's a win-win for mums."
Dr. Colin Michie, Chair of the Nutrition Committee at the Royal College of Paediatrics and Child Health, said: "Although it has a relatively small sample size, this is an important study as it builds on the limited data currently available in this area.
"The findings are particularly valuable and interesting as they suggest that altering weaning patterns can have a direct impact on a child's food selection when they get older.
"In other words, adjusting weaning could well help tackle the high rates of obesity currently found in the UK. This could be a key element in the fight to prevent overweight children becoming obese adults."
But baby-led weaning may not stop the child becoming a fussy eater though - a similar number of youngsters in both groups were deemed by their parents to be "picky" about the foods they would eat.