Effects of increasing dietary protein and fibre intake with lupin on body weight and composition and blood lipids in overweight men and women

Abstract

Background: Lupin kernel flour (LKF) is a novel food ingredient that is high in protein and fibre. We have previously shown that partial substitution of refined wheat-derived carbohydrate in bread with protein and fibre from LKF can reduce appetite and energy intake acutely. In addition, several studies have suggested that lupin may reduce cholesterol concentrations and benefit glucose and insulin metabolism. Aim: The aim of this study was to investigate the effects on body weight and composition and blood lipids, glucose and insulin of an ad libitum LKF-enriched diet higher in dietary protein and fibre. Subjects and methods: A total of 88 overweight and obese men and women were recruited for a 16-week parallel-design randomized controlled trial. Participants replaced 15-20% of their usual daily energy intake with white bread (control) or LKF-enriched bread (lupin) in an ad libitum diet. Measurements of body weight and composition, and fasting blood biochemical measurements were performed at baseline and 16 weeks. The primary analysis included 74 participants (37 per group) who completed the intervention. Results: At baseline, mean ( ± s.d.) body mass index and total cholesterol were 30.6 ± 3.5 kg m À2 and 5.37 ± 0.94 mmol l À1 , respectively. Estimated (mean between-group difference (95% confidence interval)) protein (13.7 (2.28, 25.0) g per day) and fibre (12.5 (8.79, 16.2) g per day) intakes were higher during the intervention with lupin than with control. For lupin relative to control, the net effects on body weight (À0.4 (À1.3, 0.6) kg), fat mass (À0.5 (À1.1, 0.2) kg) and percentage (À0.5 (À1.1, 0.1)%), plasma leptin (À1.66 (À4.91, 1.59) ng ml À1 ) and adiponectin (0.20 (À0.73, 1.13) mg l À1 , as well as serum total cholesterol (À0.08 (À0.38, 0.22) mmol l À1 ), triglycerides (0.09 (À0.10, 0.21) mmol l À1 ), glucose (0.10 (À0.11, 0.30) mmol l À1 ) and insulin (0.40 (À1.20, 2.00) mU l À1 ) were not significant. Conclusions: This study does not support the proposal that an ad libitum diet enriched in LKF resulting in moderate changes in both protein and fibre intakes can benefit body weight and composition or fasting blood lipids, glucose and insulin concentrations in overweight men and women with mildly elevated total cholesterol concentrations.

Effects of lupin-enriched foods on body composition and cardiovascular disease risk factors: a 12-month randomized controlled weight loss trial

“…We recently reported that an ad libitum lupin flour-enriched diet higher in dietary protein and fibre consumed over 4 months did not significantly influence body weight or composition in overweight individuals. 11 There is some evidence that longer-term regular consumption of increased protein 36,37 Abbreviations: BMI, body mass index; HDL, high-density lipoprotein; HOMA-IR, homeostasis model assessment of insulin resistance; LDL, low-density lipoprotein. a Between-group differences analysed using the independent samples t-test and the w 2 test for categorical variables.…”

“…Body composition was measured with dual-energy X-ray absorptiometry (GE Lunar Prodigy, GE Lunar Corporation, Madison, WI, USA) by a trained researcher. 11 The exclusion criteria for the dual-energy X-ray absorptiometry scan included a chance of pregnancy, a recent barium test or nuclear medicine scan. At the start of each session, quality assurance and quality control tests were performed.…”

“…10 It is commonly used as a minor food ingredient in baked foods, but can be used to partially replace wheat flour in foods such as bread and pasta, resulting in significant increases in protein and fibre levels. 11,12 These foods remain palatable and are acceptable to consumers. 12 We have previously shown that high protein and fibre lupin flour-enriched bread, with 40% wheat flour replacement, significantly reduced appetite and energy intake acutely.…”

“…26 Furthermore, acute reductions in postprandial glucose and insulin have been demonstrated with lupin flour-enriched bread consumption, 12,27 but longer-term effects are not clear. 11 The effects of a lupin-enriched diet on body weight, body composition and cardiovascular disease risk factors in the setting of weight loss and longer-term maintenance of weight loss have not been investigated.…”

The health benefits of sweet lupin seed flours and isolated proteins

“…The others are blind studies on model foods containing whole kernel flour: lupin bread in the former (Hodgson, Lee, Puddey, Sipsas, Ackland, Beilin, et al, 2010) and a portfolio of different lupin foods in the latter (Belski, Mori, Puddey, Sipsas, Woodman, Ackland, et al, 2011). Both studies, involving only subjects with normal or borderline initial cholesterol levels, were essentially inactive on cholesterol.…”