Efeito da ingestão dos chás verde (Camellia sinensis) e de hibisco (Hibiscus sabdariffa) sobre o metabolismo energético, sensação de saciedade e ingestão alimentar de indivíduos saudáveis.

Abstract

Alternative strategies for treating obesity have become increasingly popular, however, often without scientific evidence of effectiveness. In this sense, the present work aimed to evaluate the effect of green (Camellia sinensis) and hibiscus (Hibiscus sabdariffa) teas on energy metabolism, subjective feelings of satiety and food intake of healthy individuals. An experimental, randomized, open, controlled study with 21 healthy subjects of both sexes was developed. After a 12-hour fasting period, the volunteers ate standardized breakfast containing green tea, hibiscus tea or water. Resting energy expenditure (REE) and respiratory quotient (RQ) were assessed by means of indirect calorimetry at fasting and 40, 120 and 240 minutes after ingestion of standard breakfast. Oxidated substrate rates (carbohydrates, proteins, lipids) were calculated at fasting times and 240 minutes after standard breakfast ingestion. Kjeldhal method was used for GER correction and calculation of oxidized substrates of urinary nitrogen excreted from fasting times and after 240 minutes of breakfast ingestion. Subjective sensations related to satiety (hunger, satiety, fullness and prospective food intake) were reported by the volunteers through visual analog scale (VAS) at fasting times, and after breakfast (immediately after, 60, 120 and 180 minutes). Dietary intake of the first prospective meal at standard breakfast, as well as dietary intake on the day of treatment, were reported by the volunteers through dietary records, which were later converted into energy and macronutrients. The repeated measures test with the aid of SPSS version 20.0 software was used for data analysis. Green tea intake significantly increased REE (with or without urinary nitrogen correction) by 7,2±11,7% and 6,9±10,9%, respectively, after 240 minutes of test meal intake compared with fasting time in water treatment (difference GER green tea treatment: nitrogen +91,0±157,6kcal, p=0,041; non-nitrogen +88,2±146,1kcal, p=0,042). In the water treatment it was observed, after 240 minutes of the test meal intake, that the nitrogen and non-nitrogen GEN were -4,7±8,9% and -5,0±9,1%, respectively, compared to the evaluation during fasting (GER difference: nitrogen -6,4±122,1kcal; non-nitrogen - 66,4±115,1kcal). The GER of the hibiscus tea treatment, although higher, was not statistically different from the water (difference GER hibiscus treatment: nitrogen - 3,0±174,7kcal, -0,2±12,4%, p=0,096; non-nitrogen +11,2±171,1kcal, 0,9±12.2% (p=0,140). After 240 minutes of eating standardized breakfast, it was observed that the QR of green tea (0,75±0,05), hibiscus tea (0,76±0,06) and water (0,78±0,07) did not differ (drink effect: p=0,180; time x drink interaction: 0,613). Lipid oxidation after 240 minutes of standardized breakfast intake was higher in green tea treatment (4,6±2,1g/hour) compared to hibiscus tea (3,9±1,4g/hour) and water (3,6±1,8g/hour), but this difference was not significant (effect of drink: p=0,167; interaction time x drink: p=0,281). The rate of carbohydrate and protein oxidation was also no different between treatments (p>0,050). The area under the curve (iAUC) of the subjective sensations, reported in VAS for hunger, satiety and fullness, did not differ between green tea and water treatment (p=0,693; p=0,950; p=0,537 respectively). Prospective food intake reported in VAS did not differ in any treatment (water and green tea p=0,860; hibiscus water and tea p=0,633). The iAUC of hibiscus tea, when compared to water treatment, was different in hunger EVA (iAUC hibiscus 533,8±305,1cm.min; p= 0,016); satiety (iAUC hibiscus 1381,0±294,2cm.min; p=0,003) and fullness (iAUC hibiscus 1344,0±320,1cm.min; p=0,020). The energetic intake of the first meal after the breakfast test (609,4±246,1kcal), green tea (577,6±211,5kcal) and hibiscus tea (690,4±447,3kcal) did not differ in any treatment (p=0,906). The energy intake throughout the day of water treatment (1587,7±475,3kcal), green tea (1501,8±511,8kcal) and hibiscus tea (1726,1±767,9kcal) was also no different between treatments (p=0,920), as well as macronutrients (p>0,050). It was concluded that acute intake of green tea increased energy metabolism by approximately 7%, but hibiscus tea did not show the same effect. Hibiscus tea reduced subjective feelings of hunger and increased feelings of satiety and fullness, but green tea did not. Green tea and hibiscus tea did not alter subsequent food intake.