In other words, the drop in resting metabolic rate is expected due to the decrease in body size. The use of meta-analysis in this area of research is useful because it allows for a systematic examination of the many variables involved. It is, of course, limited by the range of studies available.
In addition, the calorie level is rarely adjusted according to individual needs; therefore the actual calorie deficit per individual is an important confounding variable. Based on the above reviews, we can revisit the controversial issues delineated in the introduction of this paper, and apply these issues to a family physician's practice.
One of the main points to be made is the potential impact of dietary intake, especially total calories, calorie deficits and grammes of protein per kilogram body weight. Further work is necessary to determine whether milder calorie deficits with adequate protein in combination with strength training can positively affect resting metabolic rate.
In contrast to Kraemer and colleagues' work, the majority of the studies point to a reduction in short-term resting metabolic rates that is greater than can be explained by the loss of body mass or fat-free mass over the same time period. Unfortunately, there has been very little work done over the last few years regarding the duration of this phenomenon.
Wadden and colleagues' work indicates that this disproportionate reduction reflects metabolic processes associated with the hypocaloric dieting itself. When calorie balance is resumed, the resting metabolic rate is dependent on the new body mass, especially fat-free mass. When they get to goal weight their metabolic rate is severely depressed, and they can experience almost immediate weight gain if they resume their prior higher calorie intakes. Recent studies have not continued to measure changes in resting metabolic rate for extended periods to determine whether the reductions are self-limiting.
Again, the work of Wadden and colleagues supports a self-limiting hypothesis. Lastly, exercise does not appear to negate this reduction in resting metabolic rate or fat-free mass. This may have been due to insufficient calories, protein or exercise stimulus in terms of frequency. Family practice physicians can facilitate healthy and successful weight management among their patient populations by heeding the following tips: i determine long-term weight goals based on obtaining a body mass index under 27, if possible 25; ii determine short-term weight goals based on a reduction of 1 to 2 body mass index units approximately 4.
Continue to support patient through this cyclical process until body mass index is at least under 27, if not at Based on patients' medical history and preferences, appropriate individualized diet and exercise prescriptions should be developed.
This is best approached with a health care team including a physician, registered dietitian and exercise physiologist. Through this slow and thought-ful process of cycles of weight loss and weight maintenance it is thought that patients will be able to prevent the more debilitating cycles of rapid weight loss, short-term reductions in metabolic rate and rapid weight gain.
National Heart Lung and Blood Institute. Bethesda: National Institutes of Health, Effect of caloric restriction and excessive caloric intake on energy expenditure. Am J Clin Nutr ; 24 : — Lansky D, Brownell KD. Estimates of food quantity and calories: errors in self-reporting. Am J Clin Nutr ; 35 : — Long-term effects of dieting on resting metabolic rate in obese outpatients. JAMA ; 6 : — Forbes G.
Human Body Composition. New York: Springer-Verlag, Ravussin E, Bogardus C. Relation of genetics, age, and physical fitness to daily energy expenditure and fuel utilization. Am J Clin Nutr ; 49 : — American Dietetic Association. Position of the American Dietetic Association on weight management. J Am Dietetic Assoc ; 97 1 : 71 — Oxford University Press is a department of the University of Oxford.
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Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Introduction. Concluding remarks. Effects of dieting and exercise on resting metabolic rate and implications for weight management. Josephine Connolly , Josephine Connolly. Oxford Academic. Age — metabolism slows with age due to loss of muscle tissue, but also due to hormonal and neurological changes.
Growth — infants and children have higher energy demands per unit of body weight due to the energy demands of growth and the extra energy needed to maintain their body temperature. Gender — generally, men have faster metabolisms because they tend to be larger. Genetic predisposition — your metabolic rate may be partly decided by your genes. Hormonal and nervous controls — BMR is controlled by the nervous and hormonal systems.
Hormonal imbalances can influence how quickly or slowly the body burns kilojoules. Environmental temperature — if temperature is very low or very high, the body has to work harder to maintain its normal body temperature, which increases the BMR. Infection or illness — BMR increases because the body has to work harder to build new tissues and to create an immune response. Amount of physical activity — hard-working muscles need plenty of energy to burn.
Regular exercise increases muscle mass and teaches the body to burn kilojoules at a faster rate, even when at rest. Drugs — like caffeine or nicotine, can increase the BMR. Dietary deficiencies — for example, a diet low in iodine reduces thyroid function and slows the metabolism.
Thermic effect of food Your BMR rises after you eat because you use energy to eat, digest and metabolise the food you have just eaten. For example: Fats raise the BMR 0—5 per cent. Carbohydrates raise the BMR 5—10 per cent. Proteins raise the BMR 20—30 per cent. Hot spicy foods for example, foods containing chilli, horseradish and mustard can have a significant thermic effect.
Energy used during physical activity During strenuous or vigorous physical activity, our muscles may burn through as much as 3, kJ per hour. The energy expenditure of the muscles makes up only 20 per cent or so of total energy expenditure at rest, but during strenuous exercise, it may increase fold or more.
Metabolism and age-related weight gain Muscle tissue has a large appetite for kilojoules. The more muscle mass you have, the more kilojoules you will burn. People tend to put on fat as they age, partly because the body slowly loses muscle. It is not clear whether muscle loss is a result of the ageing process or because many people are less active as they age.
However, it probably has more to do with becoming less active. Research has shown that strength and resistance training can reduce or prevent this muscle loss. If you are over 40 years of age, have a pre-existing medical condition or have not exercised in some time, see your doctor before starting a new fitness program. Hormonal disorders of metabolism Hormones help regulate our metabolism. A practical demonstration of measuring metabolic rate using a carbon dioxide probe.
Metabolic rate can also be measured with a respirometer. Watch the video below to see how this is done. A practical demonstration of measuring metabolic rate using a respirometer. Phylogeny of hammerhead sharks Family Sphyrnidae inferred from mitochondrial and nuclear genes.
Molecular Phylogenetics and Evolution. Lisney T. Behavioural assessment of flicker fusion frequency in chicken Gallus gallus domesticus. Little A. Evolutionary affinity of billfishes Xiphiidae and Istiophoridae and flatfishes Plueronectiformes : independent and trans-subordinal origins of endothermy in teleost fishes. Loop M. Temporal modulation sensitivity of the cat: I.
Behavioral methods. Lowe C. Metabolic rates of juvenile scalloped hammerhead sharks Sphyrna lewini Marine Biology. Lutz P. Effects of temperature on gas exchange and acid—base balance in the sea turtle Caretta caretta at rest and during routine activity. McComb D. Temporal resolution and spectral sensitivity of the visual system of three coastal shark species from different light environments.
Physiological and Biochemical Zoology. McGill B. An allometric vision and motion model to predict prey encounter rates.
Evolutionary Ecology Research. McKeever S. The biology of the golden-mantled ground squirrel, Citellus lateralis. Ecological Monographs. McNab B. The influence of food habits on the energetics of eutherian mammals. Makarieva A. Mean mass-specific metabolic rates are strikingly similar across life's major domains: evidence for life's metabolic optimum. Meier P. Relative brain size within the North American Sciuridae.
Journal of Mammalogy. Meneghini K. The electroretinogram of the iguana and Tokay gecko. Mercer J. The effects of Cenozoic global change on squirrel phylogeny. Murphy W. Using genomic data to unravel the root of the placental mammal phylogeny. Genome Research. Myers P. The Animal Diversity Web. Naro-Maciel E. Evolutionary relationships of marine turtles: a molecular phylogeny based on nuclear and mitochondrial genes.
Navarret A. Energetics and the evolution of human brain size. Orme C. Caper: comparative analysis of phylogenetics and evolution in R. Methods in Ecology and Evolution. Pagel M. Inferring the historical patterns of biological evolution. Paladino F. Respiratory physiology of adult leatherback turtles Dermochelys coriacea while nesting on land.
Chelonian Conservation and Biology. Palmer J. The Art of Radiometry. Pauls R. Energetics of the red squirrel: a laboratory study of the effects of temperature, seasonal acclimatization, use of the nest and exercise. Journal of Thermal Biology. Pawar S. Dimensionality of consumer search space drives trophic interaction strengths. Perelman P. A molecular phylogeny of living primates. PLoS Genetics.
Platel R. Brain weight-body weight relationships. In: Gans C. Biology of the Reptilia. Porter T. Contributions to the study of flicker. R Development Core Team. R Foundation for Statistical Computing; Vienna: R: a Language and Environment for Statistical Computing. Ridolfi K. Animal Diversity Web. Rogowitz G. Evaluation of thermal acclimation of metabolism in two eurythermal lizards, Anolis cristatellus and A.
Rohlf F. Comparative methods for the analysis of continuous variables: geometric interpretations. Rubene D. The presence of UV wavelengths improves the temporal resolution of the avian visual system.
Sato K. Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans. Schoch R. Preliminary description of a new late Paleocene land-mammal fauna from South Carolina, U. Schwartz S. McGraw-Hill; New York: Visual Perception: a Clinical Orientation. Age- and gender-related changes in body size, adiposity, and endocrine and metabolic parameters in free-ranging rhesus macaques.
Sheppard D. Seasonal changes in body and adrenal weights of chipmunks Eutamias Journal of Mammalogy. Shumake S. Critical fusion frequency in rhesus monkeys. The Psychological Record. Sibly R. Wiley-Blackwell; Oxford: Metabolic Ecology, a Scaling Approach. Southwood A. Sound, chemical, and light detection in sea turtles and pelagic fishes: sensory-based approaches to bycatch reduction in longline fisheries.
Endangered Species Research. Stevens M. Predator perception and the interrelation between different forms of protective coloration. Motion dazzle and camouflage as distinct anti-predator defences. Stewart R. Energy transfer and female condition in nursing harp seals Phoca groenlandica. Holarctic Ecology. Tansley K. Some aspects of the electroretinographic response of the American red squirrel, Tamiasciurus hudsonicus loquax.
Journal of Cellular and Comparative Physiology. Tatler B. Temperature and the temporal resolving power of fly photoreceptors. Terres J. Wings Books; New York: Vogel S. Modes and scaling in aquatic locomotion. A neurological comparative study of the harp seal Pagophilus groenlandicus and harbor porpoise Phocoena phocoena brain. The Anatomical Record. Watanabe Y. The slowest fish: swim speed and tail-beat frequency of Greenland sharks. Journal of Experimental Marine Biology and Ecology.
White C. The scaling and temperature dependence of vertebrate metabolism. Biology Letters. Widder E. Bioluminescence in the ocean: origins of biological, chemical, and ecological diversity. Wiens J. Why does a trait evolve multiple times within a clade? Repeated evolution of snakelike body form in squamate reptiles. Williams R. Flicker detection in the albino rat following light-induced retinal damage. Physiology and Behaviour.
Winchester C. University of Missouri; Columbia: Seasonal and Metabolic Rhythms in the Domestic Fowl. Woo K. Discrimination of flicker fusion rates in the reptile tuatara Sphenodon Naturwissenschaften.
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