• Energy Research

AbstractAimsTo establish which components of energy balance mediate the clinically significant weight loss demonstrated with use of cotadutide, a glucagon‐like peptide‐1 (GLP‐1)/glucagon receptor dual agonist, in early‐phase studies.Materials and MethodsWe conducted a phase 2a, single‐centre, randomized, placebo‐controlled trial in overweight and obese adults with type 2 diabetes. Following a 16‐day single‐blind placebo run‐in, participants were randomized 2:1 to double‐blind 42‐day subcutaneous treatment with cotadutide (100–300 μg daily) or placebo. The primary outcome was percentage weight change. Secondary outcomes included change in energy intake (EI) and energy expenditure (EE).ResultsA total of 12 participants (63%) in the cotadutide group and seven (78%) in the placebo group completed the study. The mean (90% confidence interval [CI]) weight change was −4.0% (−4.9%, −3.1%) and −1.4% (−2.7%, −0.1%) for the cotadutide and placebo groups, respectively (p = 0.011). EI was lower with cotadutide versus placebo (−41.3% [−66.7, −15.9]; p = 0.011). Difference in EE (per kJ/kg lean body mass) for cotadutide versus placebo was 1.0% (90% CI −8.4, 10.4; p = 0.784), assessed by doubly labelled water, and −6.5% (90% CI −9.3, −3.7; p < 0.001), assessed by indirect calorimetry.ConclusionWeight loss with cotadutide is primarily driven by reduced EI, with relatively small compensatory changes in EE.

Key Features: • The National Diet and Nutrition Survey Rolling Programme (NDNS RP) is a cross-sectional, annual survey designed to collect detailed, quantitative information on food consumption, nutrient intake and nutritional status of the general United Kingdom (UK) population aged ≥ 1.5 years. • NDNS RP uses a stratified sampling design to generate a random sample of private UK households each year and nationally representative core sample of around 1000 participants (500 adults, 500 children) each year. Design provides for additional recruitment at country level. • Data/samples include: socio-demographic; dietary assessment; anthropometry; physical activity; energy expenditure; blood and urine samples for nutritional biomarker analysis; National Health Service (NHS) Central Registry and Cancer Registry linkage, contact for further research. • NDNS RP dataset (2008-2019) comprises: dietary data (7999 adults and 7656 children); blood biomarkers (4181 adults and 2014 children); spot urine (3246 adults and 2318 children); total energy expenditure (using doubly labelled water) (419 adults and 352 children). Results published and disseminated via UK Government; survey data accessible via UK Data Service. • Stored biological samples are accessible for further health related research in the public interest through the NDNS Bioresource. • NDNS RP data underpin monitoring and development of nutrition policy. Data are used for chemical exposure risk assessment and modelling for consumer safety.

An important element in the measurement of energy budgets of free-living animals is the estimation of energy costs during locomotion. Using humans as a particularly tractable model species, we conducted treadmill experiments to test the validity of tri-axial accelerometry loggers, designed for use with animals in the field, to estimate rate of oxygen consumption (VO2: an indirect measure of metabolic rate) and speed during locomotion. The predictive power of overall dynamic body acceleration (ODBA) obtained from loggers attached to different parts of the body was compared to that of heart rate (fH). When subject identity was included in the statistical analysis, ODBA was a good, though slightly poorer, predictor of VO2 and speed during locomotion on the flat (mean of two-part regressions: R2=0.91 and 0.91, from a logger placed on the neck) and VO2 during gradient walking (single regression: R2=0.77 from a logger placed on the upper back) than was fH (R2=0.96, 0.94, 0.86, respectively). For locomotion on the flat, ODBA was still a good predictor when subject identity was replaced by subject mass and height (morphometrics typically obtainable from animals in the field; R2=0.92 and 0.89) and a slightly better overall predictor than fH (R2=0.92 and 0.85). For gradient walking, ODBA predicted VO2 more accurately than before (R2=0.83) and considerably better than did fH (R2=0.77). ODBA and fH combined were the most powerful predictor of VO2 and speed during locomotion. However, ODBA alone appears to be a good predictor and suitable for use in the field in particular, given that accelerometry traces also provide information on the timing, frequency and duration of locomotion events, and also the gait being used.

AbstractBackgroundLittle is known about population levels of energy expenditure, as national surveillance systems typically employ only crude measures. The National Diet and Nutrition Survey (NDNS) in the UK measured energy expenditure in a 10% subsample by gold-standard doubly labelled water (DLW).MethodsDLW-subsample participants from the NDNS (383 males, 387 females) aged 4–91 years were recruited between 2008 and 2015 (rolling programme). Height and weight were measured and body-fat percentage estimated by deuterium dilution.ResultsAbsolute total energy expenditure (TEE) increased steadily throughout childhood, ranging from 6.2 and 7.2 MJ/day in 4- to 7-year-olds to 9.7 and 11.7 MJ/day for 14- to 16-year-old girls and boys, respectively. TEE peaked in 17- to 27-year-old women (10.7 MJ/day) and 28- to 43-year-old men (14.4 MJ/day), before decreasing gradually in old age. Physical-activity energy expenditure (PAEE) declined steadily with age from childhood (87 kJ/day/kg in 4- to 7-year-olds) through to old age (38 kJ/day/kg in 71- to 91-year-olds). No differences were observed by time, region and macronutrient composition. Body-fat percentage was strongly inversely associated with PAEE throughout life, irrespective of expressing PAEE relative to body mass or fat-free mass. Compared with females with &lt;30% body fat, females with &gt;40% recorded 29 kJ/day/kg body mass and 18 kJ/day/kg fat-free mass less PAEE in analyses adjusted for age, geographical region and time of assessment. Similarly, compared with males with &lt;25% body fat, males with &gt;35% recorded 26 kJ/day/kg body mass and 10 kJ/day/kg fat-free mass less PAEE.ConclusionsThis first nationally representative study reports levels of human-energy expenditure as measured by gold-standard methodology; values may serve as a reference for other population studies. Age, sex and body composition are the main determinants of energy expenditure.Key Messages This is the first nationally representative study of human energy expenditure, covering the UK in the period 2008-2015. Total energy expenditure (MJ/day) increases steadily with age throughout childhood and adolescence, peaks in the 3rd decade of life in women and 4th decade of life in men, before decreasing gradually in old age. Physical activity energy expenditure (kJ/day/kg or kJ/day/kg fat-free mass) declines steadily with age from childhood to old age, more steeply so in males. Body-fat percentage is strongly inversely associated with physical activity energy expenditure. We found little evidence that energy expenditure varied by geographical region, over time, or by dietary macronutrient composition.