Three studies have once again highlighted the role fruits and vegetables play in long term weight control.
After analyzing data covering almost 125,000 healthy subjects aged 36 to 46 years old when the studies began, researchers from Harvard University and Beth Israel Deaconess Medical Center in Boston and Norwich Medical School in the UK found that flavonoids in fruits and vegetables could help prevent weight gain over time. Flavonoids are chemical compounds found in plants.
"Among fruits, an increased intake of blueberries, apples, pears, prunes, strawberries, and grapes was inversely associated with weight gain," the study authors wrote. "Increased intake of peppers and celery was also associated with less weight gain."
The study authors analyzed data from three different studies: the Health Professionals Follow-up Study (HPFS), which began 1986 and enrolled 51,529 male health professionals; the Nurses’ Health Study (NHS), which began in 1976 and enrolled 121,701 female nurses and the Nurses’ Health Study 2 (NHS II), which began in 1989 and enrolled 116, 686 nurses.
The ages of the participants ranged from 25 to 75 years old, and the subjects were followed for up to 24 years. All participants had reported their dietary habits every four years and their weight and lifestyle habits, such as exercise frequency, every two years.
According to the data, male subjects gained about 2 pounds every four years, while female subjects gained 3 to 4 pounds. Those who ate a flavonoid-rich diet gained about 20 percent less weight than other subjects.
"...Losing even small amounts of weight can improve health: losing just [11 to 22 pounds] is associated with a decrease in blood pressure and reducing body mass index," the study authors said.
Body mass index is a measurement of weight over height squared that can indicate the amount of body fat a person stores.
The study authors also stated that losing 11 to 22 pounds "is associated with a [2 to 13 percent] lower risk of cardiovascular disease events.," and that just a 10 percent increase in weight gain between ages 40 and 60 could result in a 40 to 70 percent increased chance of developing diabetes.
Study subjects seemed to get most of their flavonoids from berries, apples, oranges and orange juices, study authors said.
"Our results suggest that choosing high flavonoid fruits and vegetables, such as apples, pears, berries, and peppers, may help with weight control," the researchers wrote. "Most Americans consume less than one cup (less than two servings) of fruits and less than two cups of vegetables daily..."
The researchers say their data could change dietary recommendations for preventing weight gain in the future.
This study was published January 28 in The BMJ.
The National Institutes of Health; Biotechnology, Biological Sciences Research Council, UK; Danish Council for Strategic Research and Royal Society Wolfson funded this research.
Authors ERB and AC have received separate grants to study the relationship between blueberries and cardiovascular disease for the US Highbush Blueberry Council. No other conflicts were declared.