This study aimed investigated the acute intake effect of fresh-squeezed orange juice (FOJ), processed orange juice (POJ), and an isoenergetic orange-flavored drink (control) on postprandial response of blood serum biomarkers (glucose, insulin, leptin and adiponectin), anti-oxidatant status, and prospective food intake in lean and obese subjects.

Non-randomized crossover clinical trial, in which eligible participants (n= 36) were allocated in accordance with their body mass index in two groups, lean (n = 18, 9 women/9 men) and obese (n = 18, 9 women/9 men). Subjects of both groups intake of one single dose (5 mL/kg body weight) of isoenergetic beverages in three different phases: (1) fresh-squeezed orange juice (FOJ), (2) commercial processed orange juice (POJ) and (3) an energy and sugars-matched orange-flavored drink (control), with a washout period of seven days among each beverage. Thirty minutes after the intake of each beverage, the participants had a flavonoid-free standard breakfast, which contained coffee (infusion), milk, sugar or sweetener, white bread sandwich with lean ham and light cream cheese, salted and sweet biscuits. Posteriorly, blood samples (10 mL) were collected at 30, 60, 120 and 300 min after each intervention with a catheter installed in a vein of the arm. After blood collection, the volunteers were instructed to record all meals throughout the day, noting the amount eaten of each food. The sample number took into account variations in blood serum glucose with a type I error α = 0.05 and a type II error β = 0.2 (80% power). Primary output were the modification on glucose or insulin concentration induced by different beverages in some point of the curves. The secondary output was the antioxidant activity induced by FOJ and/or POJ. Kolmogorov Smirnov and Levene test, respectively assessed normality and homogeneity of the data. Area under the curve (AUC0-300 min) was calculated by the clearance of the appetite related-biomarkers (glucose, insulin, leptin and adiponectin) during 300 min for each trial phase Other parameters, as maximum concentration (Cmax), and time to reach maximum blood concentration (Tmax) were also estimated. AUC was determined with the trapezoidal method by Microcal Software Inc., Origin® 6.0. One-way analysis of variance (ANOVA) followed by Sidak post hoc was applied to compared the effect of interventions on appetite related-biomarkers, anti-oxidant status and beverage composition. P significance was set up ≤ 0.05.

Inclusion Criteria:

1. Healthy men and women volunteers;
2. Volunteers with BMI between 18.5 to 39.9 kg/m2.

Exclusion criteria:

1. Volunteers with BMI between more than 40 kg/m2;
2. Smokers volunteers;
3. Volunteers who are in treatment with drugs (except contraceptives), vitamins and nutritional supplements;
4. Volunteers who are dieting for weight loss;
5. Volunteers who gained or lost more than 3 kg of weight in the last 3 months;
6. Volunteers who consume more than 20 g of alcohol per day
7. Volunteers who practicing intense physical activity (more than 5 hours per week).

There was no plan to share individual participant data (IPD) to other researchers.