Rachel C. Veasey

Breakfast and exercise contingently affect postprandial metabolism and energy balance in physically active males

The present study examined the impact of breakfast and exercise on postprandial metabolism, appetite and macronutrient balance. A sample of twelve (blood variables n 11) physically active males completed four trials in a randomised, crossover design comprising a continued overnight fast followed by: (1) rest without breakfast (FR); (2) exercise without breakfast (FE); (3) breakfast consumption (1859 kJ) followed by rest (BR); (4) breakfast consumption followed by exercise (BE). Exercise was continuous, moderate-intensity running (expending approximately 2·9 MJ of energy). The equivalent time was spent sitting during resting trials. A test drink (1500 kJ) was ingested on all trials followed 90 min later by an ad libitum lunch. The difference between the BR and FR trials in blood glucose time-averaged AUC following test drink consumption approached significance (BR: 4·33 (SEM 0·14) v. FR: 4·75 (SEM 0·16) mmol/l; P=0·08); but it was not different between FR and FE (FE: 4·77 (SEM 0·14) mmol/l; P=0·65); and was greater in BE (BE: 4·97 (SEM 0·13) mmol/l) v. BR (P=0·012). Appetite following the test drink was reduced in BR v. FR (P=0·006) and in BE v. FE (P=0·029). Following lunch, the most positive energy balance was observed in BR and least positive in FE. Regardless of breakfast, acute exercise produced a less positive energy balance following ad libitum lunch consumption. Energy and fat balance is further reduced with breakfast omission. Breakfast improved the overall appetite responses to foods consumed later in the day, but abrogated the appetite-suppressive effect of exercise.

Epigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double-blind, placebo-controlled, crossover investigation.

The aim of the study was to assess the effects of oral ingestion of the ‘green tea’ polyphenol epigallocatechin gallate (EGCG) on cognitive performance, mood and localised cerebral blood flow (CBF) parameters in healthy human adults.

Vitamins and psychological functioning: a mobile phone assessment of the effects of a B vitamin complex, vitamin C and minerals on cognitive performance and subjective mood and energy

Despite being widely consumed, the effects of multi‐vitamin supplements on psychological functioning have received little research attention.

Breakfast consumption and exercise interact to affect cognitive performance and mood later in the day. A randomized controlled trial

The current study assessed the interactive effect of breakfast and exercise on cognition and mood. Twelve active males completed four trials; no breakfast-rest, breakfast-rest, no breakfast-exercise or breakfast-exercise in a randomized, cross-over design. The trials consisted of; breakfast or fast, a 2h rest, exercise (treadmill run) or equivalent rest, a chocolate milk drink, a 90 min rest and an ad libitum lunch. Cognitive performance and mood were recorded frequently throughout each trial. Data was analysed as pre-exercise/rest, during and immediately post exercise/rest and post-drink. No effects were found prior to consumption of the drink. Post-drink, fasting before exercise increased mental fatigue compared to consuming breakfast before exercise and fasting before rest. Tension increased when breakfast was consumed at rest and when exercise was undertaken fasted compared to omitting breakfast before rest. Breakfast before rest decreased rapid visual information processing task speed and impaired Stroop performance. Breakfast omission improved Four Choice Reaction Time performance. To conclude, breakfast before exercise appeared beneficial for post-exercise mood even when a post-exercise snack was consumed. Exercise reversed post-breakfast cognitive impairment in active males.

Consistency of metabolic responses and appetite sensations under postabsorptive and postprandial conditions

The present study aimed to investigate the reliability of metabolic and subjective appetite responses under fasted conditions and following consumption of a cereal-based breakfast. Twelve healthy, physically active males completed two postabsorption (PA) and two postprandial (PP) trials in a randomised order. In PP trials a cereal based breakfast providing 1859 kJ of energy was consumed. Expired gas samples were used to estimate energy expenditure and fat oxidation and 100mm visual analogue scales were used to determine appetite sensations at baseline and every 30 min for 120 min. Reliability was assessed using limits of agreement, coefficient of variation (CV), intraclass coefficient of correlation and 95% confidence limits of typical error. The limits of agreement and typical error were 292.0 and 105.5 kJ for total energy expenditure, 9.3 and 3.4 g for total fat oxidation and 22.9 and 8.3mm for time-averaged AUC for hunger sensations, respectively over the 120 min period in the PP trial. The reliability of energy expenditure and appetite in the 2h response to a cereal-based breakfast would suggest that an intervention requires a 211 kJ and 16.6mm difference in total postprandial energy expenditure and time-averaged hunger AUC to be meaningful, fat oxidation would require a 6.7 g difference which may not be sensitive to most meal manipulations.

Breakfast consumption and exercise interact to affect appetite, cognitive performance and mood later in the day

The effects of consuming or omitting breakfast and exercise or rest on cognitive function, mood and appetite were assessed in twelve healthy male participants who completed four trials; no breakfast and rest, breakfast and rest, no breakfast and exercise or breakfast and exercise in a randomized cross-over design. The study design consisted; breakfast (or continued fast), a 2 h rest, an exercise (treadmill run at 60% VO 2 max to expend ∼710 kcal) or an equivalent rest period, a liquid snack, a 90 min rest period and finally an ad libitum lunch. Cognitive task performance, mood and appetite ratings and blood glucose were recorded frequently throughout each trial. Mental fatigue ratings were significantly higher when exercise was undertaken fasted rather than following breakfast. Consuming breakfast prior to resting significantly increased speed on a Rapid Visual Information Processing task (RVIP), an effect not seen when breakfast was followed by exercise. When fasted, exercise, compared to rest, suppressed hunger during exercise and temporarily after. Consuming breakfast prior to exercise enhanced this effect, with significantly lower hunger ratings seen in this condition compared to exercise following breakfast omission. In conclusion, consuming breakfast before exercise decreased mental fatigue ratings following cognitive task completion and exercise reversed the detrimental effects of breakfast consumption on RVIP reaction time. Although the results showing short term appetite suppression following exercise when fasted support previous research, it does appear that breakfast consumption prior to exercise may augment this outcome.

Montmorency Tart cherries (Prunus cerasus L.) modulate vascular function acutely, in the absence of improvement in cognitive performance.

Cerebral blood volume and metabolism of oxygen decline as part of human ageing, and this has been previously shown to be related to cognitive decline. There is some evidence to suggest that polyphenol-rich foods can play an important role in delaying the onset or halting the progression of age-related health disorders such as CVD and Alzheimers disease and to improve cognitive function. In the present study, an acute, placebo-controlled, double-blinded, cross-over, randomised Latin-square design study with a washout period of at least 14 d was conducted on twenty-seven, middle-aged (defined as 45-60 years) volunteers. Participants received either a 60 ml dose of Montmorency tart cherry concentrate (MC), which contained 68·0 (sd 0·26) mg cyanidin-3-glucoside/l, 160·75 (sd 0·55) mean gallic acid equivalent/l and 0·59 (sd 0·02) mean Trolox equivalent/l, respectively, or a placebo. Cerebrovascular responses, cognitive performance and blood pressure were assessed at baseline and 1, 2, 3 and 5 h following consumption. There were significant differences in concentrations of total Hb and oxygenated Hb during the task period 1 h after MC consumption (P≤0·05). Furthermore, MC consumption significantly lowered systolic blood pressure (P≤0·05) over a period of 3 h, with peak reductions of 6±2 mmHg at 1 h after MC consumption relative to the placebo. Cognitive function and mood were not affected. These results show that a single dose of MC concentrate can modulate certain variables of vascular function; however, this does not translate to improvements in cognition or mood.

The Effects of Supplementation with a Vitamin and Mineral Complex with Guaraná Prior to Fasted Exercise on Affect, Exertion, Cognitive Performance, and Substrate Metabolism: A Randomized Controlled Trial

Exercise undertaken in a fasted state can lead to higher post-exercise mental fatigue. The administration of a vitamin and mineral complex with guaraná (MVM + G) has been shown to attenuate mental fatigue and improve performance during cognitively demanding tasks. This placebo-controlled, double-blind, randomized, balanced cross-over study examined the effect of MVM + G consumed prior to morning exercise on cognitive performance, affect, exertion, and substrate metabolism. Forty active males (age 21.4 ± 3.0 year; body mass index (BMI) 24.0 ± 2.4 kg/m2; maximal oxygen consumption (V̇O2max) 57.6 ± 7.3 mL/min/kg) completed two main trials, consuming either MVM + G or placebo prior to a 30-min run at 60% V̇O2max. Supplementation prior to exercise led to a small but significant reduction in Rating of Perceived Exertion (RPE) during exercise compared to the placebo. The MVM + G combination also led to significantly increased accuracy of numeric working memory and increased speed of picture recognition, compared to the placebo. There were no significant effects of supplementation on any other cognitive or mood measures or on substrate metabolism during exercise. These findings demonstrate that consuming a vitamin and mineral complex containing guaraná, prior to exercise, can positively impact subsequent memory performance and reduce perceived exertion during a moderate-intensity run in active males.

The Effect of Breakfast Prior to Morning Exercise on Cognitive Performance, Mood and Appetite Later in the Day in Habitually Active Women.

Pre-exercise nutritional practices for active females exercising for mood, cognitive and appetite benefits are not well established. Results from an initial field pilot study showed that higher energy intake at breakfast was associated with lower fatigue and higher overall mood and alertness post-exercise (all p < 0.05). In a follow-up, randomised, controlled trial, 24 active women completed three trials in a balanced, cross-over design. At 0815 h participants completed baseline cognitive tasks, mood and appetite visual analogue scales (VAS) and were administered a cereal breakfast (providing 118 or 236 kcal) or no breakfast. After 45 min, they completed a 30 min run at 65% heart rate reserve (HRR). Parameters were re-assessed immediately after exercise, then hourly until lunch (~1240 h), immediately post-lunch and at 1500 and 1900 h via a mobile phone. Breakfast enhanced feelings of relaxation before lunch (p < 0.05, d > 0.40), though breakfast was detrimental for working memory mid-afternoon (p = 0.019, d = 0.37) and mental fatigue and tension later in the day (all p < 0.05, d > 0.038). Breakfast was also beneficial for appetite control before lunch irrespective of size (all p < 0.05, d > 0.43). These data provide information on pre-exercise nutritional practices for active females and suggest that a small breakfast eaten prior to exercise can benefit post-exercise mood and subjective appetite ratings.

Collective effects of breakfast consumption and exercise on subsequent postprandial metabolism, appetite and energy balance

24.52.0 kg/m 2 and VO2peak 536 ml/kg/min), completed 4 main trials consisting of fasting and rest (FR), breakfast consumption and rest (BR), fasting and exercise (FE) and breakfast consumption and exercise (BE). Exercise consisted of running at 60 % VO2peak until � 2400 kJ had been expended. A chocolate milkshake test drink was then consumed, followed by a 90 min postprandial period preceding an ad libitum lunch to assess energy intake. Blood samples were used to determine glucose, serum insulin and NEFA concentrations along with plasma glucagon-like peptide-17‐36 (GLP-17‐36) concentrations. Expired gas was sampled to estimate energy expenditure and substrate metabolism via indirect calorimetry and visual analogue scales were used to assess appetite sensations. Due to difficulties with blood collection in some participants, data for GLP-17‐36 are presented from 10 participants and for all other blood analytes from 11 participants. Comparisons between trials were made by repeated measures ANOVA with Holm-Bonferonni post-hoc step-wise adjustment. Significance was accepted at P < 0.05. Following consumption of the test drink, peak blood glucose concentration was greater in the BE trial compared to both FE and BR (P = 0.06 and P = 0.03, respectively). The area under the curve (AUC) for blood glucose following test drink consumption was 15 % higher in the BE trial compared to BR (P = 0.006). Serum insulin AUC post-test drink tended to be greater in FR compared to all other trials (P = 0.07, P = 0.124 and P = 0.09 vs. BR, FE and BE). There was a main effect of trial on NEFA concentrations (P = 0.002). GLP-17‐36 concentrations were not significantly different between trials (P = 0.13). The AUC for hunger in response to ingestion of the test drink was greater when breakfast was omitted at rest (FR v BR: P = 0.018), which became a trend when exercise was performed (FE v BE: P = 0.053). No detectable difference was observed in lunch energy intake (P = 0.78). A main effect of trial was observed for postlunch energy, carbohydrate and fat balance (all P < 0.001). The influence of an acute bout of exercise on glucose tolerance is dependent upon prior nutritional state with no significant effect on insulin or GLP-17‐36 concentrations. Exercise reduces the impact of breakfast consumption on feelings of hunger, yet subsequent energy intake is not significantly affected. Breakfast consumption at rest results in the most positive energy balance, with breakfast omission and exercise producing the least positive energy balance.