Description of the study

We conducted a randomized clinical trial with three arms to evaluate the effect of adding either three apples, three pears, or three oat cookies on serum lipids of overweight midlife women. The amount of fiber was similar in the apples, pears and oat cookies. Secondary outcome was weight change¹.

Overweight (body mass index >25 kg/m2) women, between 30 to 50 years who were nonsmokers, with cholesterol level greater than 240 mg/dL, were invited to the study. Of 411 eligible women, 49 were randomly assigned to the three treatment groups after signing written consent form. The Ethical Committee of Rio de Janeiro State University – UERJ, Brazil, approved the protocol.

The participants were instructed by a dietician to eat a standardized hypocaloric diet, (55% energy from carbohydrates, 15% from protein, and 30% from fat) aiming at a small weight reduction that corresponded to an energy restriction of 250 kcal/day based on the baseline energy intakes and estimated expenditure (WHO, 1985)².

Participants were instructed to have a diet which includes breakfast, lunch, dinner and three snacks per day for 10 weeks. Women received the fruits or the cookies twice a month in an amount sufficient for their families, and the women were instructed to eat either three apples (300 g), three pears (300 g), or three oat cookies (60 g) per day during the follow-up. Each two weeks, the participants completed dietary records for three consecutive days, including one weekend day to evaluate compliance. Weight, height were measured monthly. Diets were adjusted every two weeks according to changes in body weight.
The main staple foods of Brazilian diet: rice and beans were used for energy adjustment. The average intake was 2,401±389 kcal/day, 2,459±464 kcal/day or 2,383±31kcal/day for the apple, pear or oat group respectively.

Study results

Results showed a significant decrease in the energy density during the follow up (- 1.23 kcal/g, p<0.04, and -1.29 kcal/g, p<0.05) for apples and pears respectively, compared to the oat group.

The energy intake also decreased significantly (-25.17 and -19.81 kcal/day) for the apple and pear group respectively, but showed a small increase (+0.93) for the oat group. Apples and pears were also associated (p<0.001) with weight reduction for the apple (-0.93 kg) and the pear (-0.84 kg) groups, whereas weight was unchanged (+0.21 kg; P=0.35) in the oat group.

Conclusion

The energy density of foods is considered a key determinant of energy intake because a large intake of a low-energy-dense diets, such as fruits, makes an excessive energy intake more difficult3, 4. Although our study did not directly address the effects of fruits on the energy density, we showed that body weight was reduced by adding fruits to the diet. These results suggest that energy densities of fruits, independent of their fiber amount can reduce energy consumption and body weight over time.