The effect of an increased intake of vegetables and fruit on weight loss, blood pressure and antioxidant defense in subjects with sleep related breathing disorders

Abstract

Objective: To assess the effect of an increased consumption of vegetables and fruit on body weight, risk factors for cardiovascular disease (CVD) and antioxidant defense in obese patients with sleep-related breathing disorders (SRBD). Design: Randomized, controlled trial of an intervention to increase the intake of vegetables to 400 g/day and fruit to 300 g/day. Dietary intake was calculated from a food frequency questionnaire. Antioxidant status was assessed with the ferric-reducing/ antioxidant power (FRAP) assay. Plasma carotenoids were biomarkers for the intake of vegetables and fruit. Setting: A hospital clinic preventing risk factors for CVD. Subjects: Subjects were 103 men and 35 women with a body mass index of 36.775.8 kg/m 2 of which 57 (86%) in the control and 68 (94%) in the intervention group completed the study. Intervention: Group-based behavioral program during 3 months. Results: The mean between group differences in body weight was À2.0% (95% CI À3.6, À0.5), Po0.0001. The mean between group difference in systolic and diastolic blood pressure (BP) was À7.1 mm Hg (95% CI: À11.6, À2.6), P ¼ 0.0022 and À3.9 mm Hg (95% CI: À7.0, À0.9), P ¼ 0.0120, respectively. The mean change in daily intake of vegetables and fruit was 12 g (95% CI: À33, 57) and À4 g (95% CI: À79, 71) versus 245 g (95% CI: 194, 296) and 248 g (95% CI: 176, 320) in the control and intervention groups, respectively. This was reflected in higher concentrations of a-carotene and b-carotene. No change in FRAP was seen. In a multiple regression analysis the change in intake of vegetables was a significant contributor (R adj 2 ¼ 0.073 (95% CI: 0.019, 0.214)) to the change in weight. Conclusion: Targeted dietary advice to increase the intake of vegetables and fruit among subjects with SRBD contributed to weight reduction and reduced systolic and diastolic BP, but had no effect on antioxidant defense measured with FRAP. Sponsorship: None.

The Effect of Increasing Fruit and Vegetable Consumption on Overall Diet: A Systematic Review and Meta-analysis

“…The majority of energy/ fat intakes did not correlate with changes in body weight in the studies reporting on these findings, with some studies acknowledging that underreporting was likely (Cox et al, 1998;Maskarinec et al1999). Only one study by Svendsen et al (2007) showed consistent results with significant decreases in body weight alongside significant decreases in fat intake. Furthermore it is probable that accuracy of reporting is not the only limitation of dietary data collection but the likelihood that keeping a record of dietary intakes may also influence choices and therefore alter usual intakes (Djuric et al, 2006).…”

“…Furthermore the study by Cox et al (1998) showed significant increases in body weight alongside a nonsignificant decrease in both energy (-24 kcals) and fat (-3%) intakes. Svendsen et al (2007) found significant decreases in body weight together with significant decreases in fat intakes of -4% and non-significant decreases in energy intake (-213 kcals). Two studies by Watzl et al (2005) and Whybrow et al (2006) showed neither significant change in body weight or energy/ fat intakes.…”

“…Most trials included subjects with a BMI of ≤ 25 kg/m 2 . Six studies reported body weight data; of these, one study reported a significant increase in body weight (Cox et al, 1998), one study reported a significant decrease in body weight (Svendsen et al, 2007) and four studies reported no significant difference in body weight post-intervention (Maskarinec et al, 1999;SmithWarner et al, 2000;Watzl et al, 2005;Whybrow et al, 2006). Examining body weight in relation to energy/ fat intakes showed that 2 studies reporting no significant change in body weight, also reported significant decreases in fat intakes of 8% (Maskarinec et al, 1999) and 4% (Smith-Warner et al, 2000), with no significant change in energy intakes.…”

“…FV are low in energy density and have high water content, allowing individuals to have larger portion sizes of these foods, whilst potentially lowering the amount of energy consumed (Svendsen et al, 2007). FV, being rich in fibre, may also promote satiety, thus reducing consumption of other foods that promote weight gain and increase disease risk (Rolls et al, 2004;Slavin, 2005).…”

A workplace feasibility study of the effect of a minimal fruit intervention on fruit intake

“…Other intervention studies have found an effect of increased fruit intake on total energy intake (23)(24)(25)(26)(27) . These intervention studies are either behavioural intervention studies, addressing several dietary and lifestyle factors among free-living individuals (24)(25)(26) , or clinical trials, implementing strict dietary regulations (23,27) . Common to all these studies is that participants were either overweight or obese and may thus have had a high motivation for weight reduction.…”