Parents completed online questionnaires every three months until their baby was a year old and then every three months until their child was three years old.
Parents of exclusively breastfed babies were more likely to perceive their babies as having sleep problems, researchers found.
Others are more cautious of the new findings such as Atlanta-based pediatrician Dr. Jennifer Shu, who wasn't part of the study.
The study published in the journal JAMA Pediatrics reveals that introducing 3-month-old infants to solid food helps them sleep longer, reduces the times they wake up in the middle of the night, and even makes serious sleep problems less likely. "The well-established benefits of breast milk need to be weighed up against the potential benefits of early introduction of solid food which displaces breast milk".
"The results of this research support the widely held parental view that early introduction of solids improves sleep", said study co-lead author Gideon Lack, professor of pediatric allergy at King's College London.
Diet is brought up most often in discussions of physical fitness and weight, but the foods you eat have a profound impact on almost all of your body's functions - including sleep.
However, a new study conducted by a team of researchers in Britain has brought to light that the babies who consume solid foods along with breast milk starting from three months usually tend to sleep better in comparison to the babies who consume only breast milk until six months of age.
First foods can include mashed or soft cooked fruit and vegetables - such as parsnip, potato, yam, sweet potato, carrot, apple or pear. The early group also slept about 17 minutes longer per day and awoke less frequently throughout the night.
They also found these benefits were long lasting - with the babies who had started eating earlier still sleeping better at one year of age.
'We found a small but significant increase in sleep duration and less frequent waking at night.
"There was an extremely strong relationship between mother's quality of life and infant sleep, which you anticipate", he added.
The US Department of Health and Human Services, the American Academy of Pediatrics, and the World Health Organization all officially recommend that infants be exclusively breastfed for the six months after birth. If there is any doubt about what's best for your baby, please seek advice from your doctor or health professional'. Participants were randomized to an early introduction group (EIG), which continued to breastfeed while nonallergenic and six allergenic foods were introduced, and a standard introduction group (SIG) that followed British infant feeding guidelines, which recommend avoiding any food consumption for around six months of exclusive breastfeeding.
She added, "However, the evidence base for the existing advice on exclusive breastfeeding is over 10 years old and is now being reviewed in the United Kingdom by the Scientific Advisory Committee on Nutrition".