41 research outputs found
Metabolic state alters economic decision making under risk in humans
Background: Animals' attitudes to risk are profoundly influenced by metabolic state (hunger and baseline energy stores). Specifically, animals often express a preference for risky (more variable) food sources when below a metabolic reference point (hungry), and safe (less variable) food sources when sated. Circulating hormones report the status of energy reserves and acute nutrient intake to widespread targets in the central nervous system that regulate feeding behaviour, including brain regions strongly implicated in risk and reward based decision-making in humans. Despite this, physiological influences per se have not been considered previously to influence economic decisions in humans. We hypothesised that baseline metabolic reserves and alterations in metabolic state would systematically modulate decision-making and financial risk-taking in humans.
Methodology/Principal Findings: We used a controlled feeding manipulation and assayed decision-making preferences across different metabolic states following a meal. To elicit risk-preference, we presented a sequence of 200 paired lotteries, subjects' task being to select their preferred option from each pair. We also measured prandial suppression of circulating acyl-ghrelin (a centrally-acting orexigenic hormone signalling acute nutrient intake), and circulating leptin levels (providing an assay of energy reserves). We show both immediate and delayed effects on risky decision-making following a meal, and that these changes correlate with an individual's baseline leptin and changes in acyl-ghrelin levels respectively.
Conclusions/Significance:
We show that human risk preferences are exquisitely sensitive to current metabolic state, in a direction consistent with ecological models of feeding behaviour but not predicted by normative economic theory. These substantive effects of state changes on economic decisions perhaps reflect shared evolutionarily conserved neurobiological mechanisms. We suggest that this sensitivity in human risk-preference to current metabolic state has significant implications for both real-world economic transactions and for aberrant decision-making in eating disorders and obesity
An overview of the recent developments on fructooligosaccharide production and applications
Over the past years, many researchers have suggested
that deficiencies in the diet can lead to disease states
and that some diseases can be avoided through an adequate
intake of relevant dietary components. Recently, a great interest
in dietary modulation of the human gut has been registered.
Prebiotics, such as fructooligosaccharides (FOS), play a key
role in the improvement of gut microbiota balance and in
individual health. FOS are generally used as components of
functional foods, are generally regarded as safe (generally
recognized as safe status—from the Food and Drug Administration,
USA), and worth about 150€ per kilogram. Due to
their nutrition- and health-relevant properties, such as moderate
sweetness, low carcinogenicity, low calorimetric value,
and low glycemic index, FOS have been increasingly used
by the food industry. Conventionally, FOS are produced
through a two-stage process that requires an enzyme production
and purification step in order to proceed with the chemical
reaction itself. Several studies have been conducted on the
production of FOS, aiming its optimization toward the development
of more efficient production processes and their potential
as food ingredients. The improvement of FOS yield and
productivity can be achieved by the use of different fermentative
methods and different microbial sources of FOS producing
enzymes and the optimization of nutritional and
culture parameter; therefore, this review focuses on the latest
progresses in FOS research such as its production, functional
properties, and market data.Agencia de Inovacao (AdI)-Project BIOLIFE reference PRIME 03/347. Ana Dominguez acknowledges Fundacao para a Ciencia e a Tecnologia, Portugal, for her PhD grant reference SFRH/BD/23083/2005