Impact of breakfast on daily energy intake - an analysis of absolute versus relative breakfast calories

<p>Abstract</p> <p>Objective</p> <p>The role of breakfast energy in total daily energy intake is a matter of debate. Acute feeding experiments demonstrated that high breakfast energy leads to greater overall intake supported by cross-sectional data of a free-living population. On the other hand, a large intraindividual analysis has indicated that a high proportion of breakfast to overall intake is associated with lower daily energy intake. To evaluate these apparently contradictory results in greater detail both ways of analysis were applied to the same data set of dietary records.</p> <p>Methods</p> <p>On an intraindividual basis total daily energy intake was related to the absolute values of breakfast energy intake or to the ratio of breakfast to overall intake, respectively. Food intake of 280 obese and 100 normal weight subjects was analyzed who recorded over 10 (obese) or 14 (normal weight) consecutive days, respectively.</p> <p>Results</p> <p>Increasing breakfast energy was associated with greater overall intake in normal weight and obese subjects. The increasing ratio of breakfast to total daily energy intake was associated with a significant reduction of overall intake on days where post-breakfast energy was significantly reduced. Correlational and multiple regression analysis support the concept that absolute breakfast calories have the strongest influence on daily energy intake.</p> <p>Conclusion</p> <p>Reduced breakfast energy intake is associated with lower total daily intake. The influence of the ratio of breakfast to overall energy intake largely depends on the post-breakfast rather than breakfast intake pattern. Therefore, overweight and obese subjects should consider the reduction of breakfast calories as a simple option to improve their daily energy balance.</p

A cross-sectional observational study of the nutritional intake of UK primary school children from deprived and non-deprived backgrounds: implications for school breakfast schemes

BACKGROUND: This study examined the nutritional intake of 9-11 year old children in Wales, UK, to assess the rationale for, and potential of, school breakfast initiatives. It also examined the possible unintended consequence of over consumption. METHODS: The study employed a cross-sectional observational design within a randomized controlled trial of a free school breakfast programme. A total of 111 primary schools were randomly assigned to an intervention condition (in which a free school breakfast programme was implemented) or a control condition (in which implementation of the scheme was delayed). Sub-samples of children completed multiple-pass 24-hr dietary recall interviews at baseline (n = 581), and 12 months later (n = 582). Deprivation was assessed for each child in terms of whether or not they were entitled to free school meals. RESULTS: Prior to the introduction of the programme, rates of breakfast skipping were low and there was little evidence of widespread nutritional deficiency. However, there was a subset of children who consumed inadequate levels of a range of vitamins and minerals and 29 % of children ate very little for breakfast (less than 100 kcal). Children that ate larger breakfasts, had higher daily intakes of all nutrients that were examined. Children from deprived backgrounds consumed significantly lower levels of several vitamins and minerals at breakfast. Following the introduction of the breakfast scheme in intervention schools, there was little difference in the nutritional quality of school versus home breakfasts (n = 35 and 211 respectively). Where children ate breakfast at both school and home (n = 33), their overall energy intake was higher, but not significantly so. CONCLUSIONS: Although the overall diet of this group of children was generally good prior to the breakfast scheme, the results suggest that such schemes could be beneficial for a subset of children who are poorly nourished and for those children who consume very little for breakfast. TRIAL REGISTRATION: Current Controlled Trials ISRCTN18336527

Bath Breakfast Project (BBP) - Examining the role of extended daily fasting in human energy balance and associated health outcomes: Study protocol for a randomised controlled trial [ISRCTN31521726]

<p>Abstract</p> <p>Background</p> <p>Current guidance regarding the role of daily breakfast in human health is largely grounded in cross-sectional observations. However, the causal nature of these relationships has not been fully explored and what limited information is emerging from controlled laboratory-based experiments appears inconsistent with much existing data. Further progress in our understanding therefore requires a direct examination of how daily breakfast impacts human health under free-living conditions.</p> <p>Methods/Design</p> <p>The Bath Breakfast Project (BBP) is a randomised controlled trial comparing the effects of daily breakfast consumption relative to extended fasting on energy balance and human health. Approximately 70 men and women will undergo extensive laboratory-based assessments of their acute metabolic responses under fasted and post-prandial conditions, to include: resting metabolic rate, substrate oxidation, dietary-induced thermogenesis and systemic concentrations of key metabolites/hormones. Physiological and psychological indices of appetite will also be monitored both over the first few hours of the day (i.e. whether fed or fasted) and also following a standardised test lunch used to assess voluntary energy intake under controlled conditions. Baseline measurements of participants' anthropometric characteristics (e.g. DEXA) will be recorded prior to intervention, along with an oral glucose tolerance test and acquisition of adipose tissue samples to determine expression of key genes and estimates of tissue-specific insulin action. Participants will then be randomly assigned either to a group prescribed an energy intake of ≥3000 kJ before 1100 each day or a group to extend their overnight fast by abstaining from ingestion of energy-providing nutrients until 1200 each day, with all laboratory-based measurements followed-up 6 weeks later. Free-living assessments of energy intake (via direct weighed food diaries) and energy expenditure (via combined heart-rate/accelerometry) will be made during the first and last week of intervention, with continuous glucose monitors worn both to document chronic glycaemic responses to the intervention and to verify compliance.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN31521726">ISRCTN31521726</a>.</p

Biochemistry and physiology of gastrointestinal somatostatin

Somatostatin, a tetradecapeptide initially isolated from the ovine hypothalamus, is widely distributed throughout the gastrointestinal tract where it may act as a hormone, local chemical messenger, or neurotransmitter to elicit many physiological actions. Release of somatostatin from D cells in the gut is regulated by mechanisms that are both dependent on and independent of cAMP. In most cases somatostatin acts to inhibit the function of its target cells. It performs this action in part via pertussis-toxin-sensitive inhibitory guanine nucleotide-binding proteins that regulate adenylate cyclase activity. Other mechanisms may involve sites of action distal to intracellular second messenger systems .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44411/1/10620_2005_Article_BF01536041.pd

Characterization of Prejunctional and Postjunctional Muscarinic Receptors of the Ascending Reflex Contraction in Rat Ileum 1

ABSTRACT The ascending reflex contraction of the small intestine involves predominantly cholinergic neurotransmission. The orally projecting neural excitatory pathway of the myenteric reflex was studied in an in vitro model of rat ileal segments. The contractile response elicited by aboral field stimulation was significantly inhibited by a range of muscarinic receptor antagonists. Methoctramine and tripitramine (both M 2 selective, pIC 50 ϭ 9.3 and 8.8, respectively), darifenacin and hexahydrosiladifenidol (both M 3 selective, pIC 50 ϭ 7.3 and 7.7, respectively), and pirenzepine (M 1 selective, pIC 50 ϭ 7.0). In radioligand binding experiments on synaptosomal and smooth muscle plasma membrane fractions, we examined whether prejunctional or postjunctional muscarinic receptors exist that could potentially contribute to the reflex contraction. In the synaptosomal fraction, the muscarinic ligand In the smooth muscle plasma membrane fraction, the K d value was 0.29 Ϯ 0.05 nM and the B max value was 770 Ϯ 29 fmol/mg. The competition studies revealed a similar ratio of potency of the respective antagonists. These data suggest that muscarinic M 2 receptors, located at prejunctional and postjunctional sites, are predominantly involved in the ascending reflex contraction. Two polarized reflexes are the principal effectors of segmental and propulsive motility of the gut: the ascending excitatory and the descending inhibitory reflex Thus, it is of physiological and clinical interest to elucidate the nature of the muscarinic receptor subtypes controlling circular muscle activity and propagating neural transmission in the myenteric plexus. Receptor-binding studies in guinea pig ileum longitudinal muscle preparations demonstrated that the majority of ileal muscarinic receptors are of the M 2 subtype (ϳ80%), whereas a minority are of the M 3 subtype (ϳ20%) with no measurable quantities of M 1 or M 4 receptor