The basic proposal of this research was to study the effect of apple consumption as dietary treatment of plasma lipids and weight loss. To assess the effect of apple adding in diet, first was necessary to standardize the total number of meals, since the serum cholesterol level is influenced by this variation. Thus, in the run-in period of the study the researchers stabilized the number of meals. The participants increased the number of meals with introduction of three supplements daily.

A possible physiological basis for the hypothesis of a protective effect of apples on serum cholesterol and body weight would be their fiber composition, so the study presents a comparison arm for the consumption of dietary fiber adjusted for total calories (oatmeal cookies). However, another possible physiological factor could be the energy density of foods. Energy density is an important determinant of energy consumption because a high intake of a diet low energy-dense food, such as fruits, makes excessive energy consumption more difficult, and few studies have been conducted on satiety and weight control and serum cholesterol. Recently (2012) discovered the presence on the apple peel a substance named ursolic acid that showed the effect in reducing body weight.

Previous studies have observed a reduction in cholesterol levels associated with consumption of apple and for to test this hypothesis, as well as weight reduction, a randomized clinical trial study with three arms where the apple was compared with an equal amount of fiber and total calories by eating oatmeal cookies and other fruit (pear).

We postulated that, if a group receive an other fruit could be excluding the possibility of the effect being attributed to the increased consumption of fruits displacing other foods and not apple effect. The pear was chosen due to its percentage of the nutritional components similar the apple. Before beginning the survey raised the consumption of apple in Brazil to assess the feasibility of such a study, if we confirmed the hypothesis of a protective effect. The apple consumption in Brazil increased in recent years. This trend was driven by the increased supply of fruit and reduction of food prices in general. Still in the pilot study survey we tested the acceptance of the introduction of three fruits in the diet of participants. The majority of the population accepted without problems to ingest three fruits daily. Our initial hypothesis was that fruit consumption in low-income populations would be low, which was confirmed. To ensure increased consumption of fruits, these were purchased and delivered to the participants, along with transportation vouchers, weekly. The oat cookies were also produced by the staff and offered at no cost to the participants. The frequency of the number of daily meals was low in the study population at baseline: 3.8 meals per day and could encourage major changes in lipid metabolism, associated to the frequency of meals. Then, the number of meals was increased to six meals a day, including breakfast, lunch, dinner and three snacks between meals and supplement: apple, pear or oat cookies. The dietary prescription was based on the eating habits of participants at baseline, changing only the number of meals and by introduce fruits or biscuits during treatment.