Consuming polydextrose in a mid-morning snack increases acute satiety measurements and reduces subsequent energy intake at lunch in healthy human subjects

Abstract

Polydextrose (Litesse®, DuPont) is a polysaccharide that is partially fermented in the colon. Evidence suggests that polydextrose increases satiety when consumed over several weeks; however studies assessing its acute effects on satiety are lacking. This study therefore aimed to assess the impact of different doses of polydextrose on satiety and energy intake at subsequent meals during a test day. Three yogurt-based drinks containing different amounts of polydextrose (0, 6.25 and 12.5 g) were tested using a randomised, single-blinded, placebo controlled, cross-over design. Thirty-four healthy male and female volunteers were provided with a standard breakfast, then consumed the test product mid-morning, 90 min before an ad libitum lunch, which was followed by an ad libitum dinner. Visual analogue scales were used to measure subjective ratings of appetite, liking and discomfort. Consuming 6.25 and 12.5 g polydextrose increased satiety and decreased appetite compared to control immediately after consumption. A reduction in energy intake (218.8 kJ) at lunchtime was observed for 12.5 g polydextrose. This reduction in energy intake was not compensated for at dinner. This study suggests that polydextrose may aid in increasing satiety feelings post consumption and also reduce energy intake as a result.

Introduction

The worldwide prevalence of obesity is increasing dramatically (Canoy & Buchan, 2007), placing an increasing burden on health service providers and reducing quality of life and life expectancy for obese individuals (Rennie & Jebb, 2005). Obesity is associated with a number of co-morbidities including type-2 diabetes, hypertension, cardiovascular disease and musculoskeletal problems (Department of Health Public Health Research Consortium Law, Power, Graham, & Merrick, 2007), therefore a variety of approaches to weight loss and weight maintenance have been proposed in order to attenuate the rise in obesity incidence.

Helping consumers to feel less hungry is an approach to weight management that is an area of substantial research because it has the potential to decrease inter-meal hunger and hence reduce overall energy intake. Appetite can be divided into two key components: satiety, defined as the inhibition of hunger and eating and increase in fullness that arises as a result of consuming food, and satiation, the process that brings eating to a halt and therefore controls meal size (Blundell et al., 2010). The regulation of satiety and satiation is influenced by a wide variety of factors that involve the interaction between physiological processes in the brain and body, and social and physical environments (Blundell, 1991), however the inclusion of certain foods, for example fibre, in the diet has been shown to influence satiety and may therefore assist with weight management (Slavin & Green, 2007).

Fibre has been shown to have a variety of health benefits, with a diet high in fibre being linked to a reduced risk of diseases including diabetes, cancer, heart disease and obesity (Slavin & Green, 2007). There is also considerable evidence to suggest fibre in general has an impact on satiety, but these effects are dependent on the specific type of dietary fibre, its physical properties and its physiological behaviour within the gut (Kristensen & Jensen, 2011). The mechanisms in which fibre affects satiety are not fully understood and vary depending on the type of fibre, however there is some evidence suggesting the link between fibre and satiety may be a result of delayed gastric emptying, modified blood glucose response, stimulation of gut hormone release or short chain fatty acid (SCFA) generation in the colon (Calame et al., 2011, Lyly et al., 2010).

Polydextrose (Litesse®, DuPont) is a randomly bonded polymer of glucose, containing minor amounts of bound sorbitol and citric acid with a predominance of 1,6 pyranose glycosidic links but all possible linkages with the glycosidic carbon of glucose are present (Auerbach et al., 2007, Lahtinen et al., 2010). It has low energy density (4.19 kJ/g) and is used to replace sugar and fat, whilst maintaining mouthfeel, in a wide variety of food applications including clear beverages, confectionary and sugar-free products. It is widely recognised as a soluble dietary fibre (Raninen, Lappi, Mykkänen, & Poutanen, 2011) that is not digested in the upper gastro-intestinal tract but is partially fermented in the large intestine, generating SCFA, and due to the slow fermentation polydextrose is well tolerated in doses up to 90 g/day with no laxative effect (Flood, Auerbach, & Craig, 2004). Due to the complex structure and nature of the glycosidic bonds polydextrose is resistant against digestion with mammalian intestinal enzymes and is fermented only partially by the intestinal microbiota (Achour et al., 1994, Figdor and Bianchine, 1983). There is limited data available on the effect of consuming polydextrose on appetite, however some studies have demonstrated a relationship between polydextrose and satiety: King et al. conducted a study in which lean volunteers consumed 200 g yogurt containing 25 g polydextrose daily for 10 d and showed a significant reduction in energy intake at an ad libitum meal compared with a control yogurt; although this effect only reached significance when the energy content of the yogurts was accounted for (King, Craig, Pepper, & Blundell, 2005). Schwab et al. demonstrated that consuming a drink enriched with 16 g polydextrose daily for 12 weeks resulted in reduced ratings of hunger 180 min after consumption; however appetite measurements were not the primary outcome measure of this study, which investigated the effects of polydextrose on glycaemia in subjects with abnormal glucose metabolism (Schwab, Louheranta, Torronen, & Uusitupa, 2006).

The data on polydextrose and satiety, however, are conflicting. Willis et al. compared the effects of different fibres on satiety by incorporating them into a muffin which was given to healthy subjects to consume at breakfast and subjective appetite ratings were collected using visual analogue scales for three hours. Whilst resistant starch and corn bran had significant effects on satiety, the muffin containing 9.5 g polydextrose had very little effect on satiety and was similar to the low fibre control muffin in its behaviour (Willis, Eldridge, Beiseigel, Thomas, & Slavin, 2009). In a study assessing the effects of a milk drink containing 3 g polydextrose on insulin and glucose levels, no differences in satiety ratings were found between the test and control drinks (Lummela et al., 2009).

As demonstrated by the studies described above, existing data on polydextrose and satiety is inconclusive, relates to a variety of different doses, and the studies which have shown a positive effect involve medium- to long-term consumption of polydextrose prior to acute measurements of subjective ratings of satiety. Based on the evidence available, we postulated that polydextrose may influence short-term satiety. Previous studies on polydextrose have used only subjective measurements; therefore the aim of this study was to determine whether consuming polydextrose in an acute intervention can show a response in measurements of satiety and energy intake over a whole day.