In the study, 240 people diagnosed as clinically obese with metabolic syndrome were asked to either follow the A.H.A’s guidelines for losing weight, or consume the minimum 30 grams of fiber each day, and no physical activity was required.
Both groups lost weight at the end of the study, and the 1.4 pounds difference between the two groups was statistically insignificant.
Participants who followed the A.H.A’s guidelines had to eat fish twice a week, consume at least 30 grams of fiber-rich foods a day and less than 300 grams of cholesterol per day. For protein intake, this group was asked to get it from vegetables and lean meats, and reduce as much as possible sugar, sodium, and sweetened beverages. Reduction of alcohol intake was a strong requirement.
Other strict rules imposed by A.H.A guidelines included reducing calorie intake, with 50 to 55 percent of calories coming from carbohydrates, 15 to 20 percent from protein, and 30 to 35 percent from fats, as well as less than 1 percent from trans fats.
A.H.A recommendation is difficult to follow, but experts say the 30 grams of fiber each day is the real key of success.
Researchers saw a good opportunity to start their own study after the publication in 2012 of a paper in Archives of Internal Medicine which showed that people who exercised less but increased their intake of fresh fruit and vegetables were more ready to improve their diet and physical activity compared to people who were overwhelmed with rigorous recommendations.
The 240 participants, aged between 21 and 70, had a body mass index (BMI) between 30 and 40 which made them clinically obese.
After one year, the A.H.A.-diet group lost on average 6 pounds, while those in the fiber group lost 4.6 pounds. The difference of 1.4 pounds was not considered statistically significant. Additionally, both groups displayed lower total cholesterol, lower blood pressure, and lower triglyceride levels.
The study was published in the journal Annals of Internal Medicine.