Diets That Include Healthy Fats May Not Cause Weight Gain
Recent data supports emphasis on eating more calories from nuts, vegetables, beans, fish, and minimally processed whole grain.
(HealthDay News) -- An eating plan that includes healthy fats such as olive oil and nuts isn't likely to cause weight gain, according to a study published in The Lancet Diabetes & Endocrinology.
The study included 7447 women and men in Spain, aged 55 to 80. The participants ate 1 of 3 eating plans: an unrestricted-calorie Mediterranean diet rich in olive oil; an unrestricted-calorie Mediterranean diet rich in nuts; or a low-fat diet meant to avoid all dietary fat. All of the participants had type 2 diabetes or 3 or more cardiovascular risk factors. More than 90% were overweight or obese.
After 5 years, total fat intake fell from 40.0% to 37.4% in the low-fat diet group, and rose in both Mediterranean diet groups, from about 40% to 42%. The percentage of proteins and carbohydrates decreased in both Mediterranean diet groups. Participants lost an average of 0.88 kg per person in the olive oil group, 0.60 kg in the low-fat diet group, and 0.40 kg in the nut group. The low-fat group had an increase in waist circumference of 1.2 cm per person, the olive oil group saw an increase of 0.85 cm, and the nut group had the smallest increase of 0.37 cm.
"Energy density and total caloric contents can be similarly misleading. Rather, modern scientific evidence supports an emphasis on eating more calories from fruits, nuts, vegetables, beans, fish, yogurt, phenolic-rich vegetable oils, and minimally processed whole grains; and fewer calories from highly processed foods rich in starch, sugar, salt, or trans-fat," Dariush Mozaffarian, MD, DrPH, from the School of Nutrition Science & Policy at Tufts University in Boston, writes in an accompanying commentary. "Dietary guidelines should be revised to lay to rest the outdated, arbitrary limits on total fat consumption. Calorie-obsessed caveats and warnings about healthier, higher-fat choices such as nuts, phenolic-rich vegetable oils, yogurt, and even perhaps cheese, should also be dropped."
Hojiblanca, Patrimonio Comunal Olivarero donated extra-virgin olive oil for the study, and the California Walnut Commission, Borges, and Morella Nuts donated nuts.