The popular adage "you are what you eat" is literally true, finds a new research that claims a person's diet has a profound influence on his or her brain.
The findings offer insight into the neurobiological factors behind the obesity epidemic in the world.
In addition, the study exposed changes in brain chemistry due to diet and weight gain.
Obesity has been linked to rises in diabetes, stroke, and heart attacks, among other disorders, but the new research has added another dimension to understanding how obesity rates have more than doubled in the past 30 years.
The new findings show that disruptions in the sleep/wake cycle lead to weight gain, impulsivity, slower thinking, and other physiological and behavioural changes.
This could be particularly important for people who do shift work.
The study also showed that pregnant mice fed a high-fat diet produced pups that were longer, weighed more, and had reduced insulin sensitivity - factors that indicate a predisposition toward obesity and diabetes. In addition, despite no further exposure to a high-fat diet, these pups passed on those same traits to their offspring.
Feeding high-fat food to pregnant mice can affect the brain development of their offspring, causing the pups to be more vulnerable to obesity and to engaging in addictive-like behaviours in adulthood, found the researchers.
Besides, they found that brain pleasure centres became progressively less responsive in rats fed a diet of high-fat, high-calorie food - changes previously seen in rats as they became addicted to cocaine or heroin.
Furthermore, the animals became less likely to eat a well-balanced, nutritious diet even when the less-palatable healthy food was all that was available.
The finding may have implications for humans, as the diets were similar to those in developed countries.
Other research findings showed that there is considerable evidence that body weight and fat mass are highly heritable traits and have strong genetic determinants.
This offers the potential to identify specific brain-derived factors contributing to obesity, eating behaviour, and responses to food.
"The brain is the foundation of all behaviour, including eating. With the growing rates of obesity in industrialized nations, brain research is important to understanding the underlying neurobiological responses to high-fat diet," said press conference moderator Dr. Ralph DiLeone, of Yale University School of Medicine, an expert on the neural mechanisms of food intake and behaviour.
The study was reported at Neuroscience 2009, the Society for Neuroscience's annual meeting.