Benders'dictionary of nutrition and food technology

305metabolic equivalent (MET) Unit of measurement of heat productionby the body; 1 MET = 50 kcal (210 kJ)/hour/m 2 bodysurface area.metabolic rate Rate of utilisation of energy. See basal metabolicrate.metabolic syndrome insulin resistance, hypertriglyceridaemia,low hdl, hypertension and hyperglycaemia, associatedwith abdominal obesity, and sometimes also involving polycysticovary syndrome and gout. Sometimes called ‘syndromeX’. Mainly due to the metabolic effects of adipose tissuewithin the abdominal cavity (as opposed to subcutaneousadipose tissue). Commonly progresses to type II diabetes mellituswhen the capacity of the β-islet cells of the pancreas tosecrete insulin in response to persistent hyperglycaemia isexhausted.metabolic weight energy expenditure and basal metabolic ratedepend on the amount of metabolically active tissue in the body,not the total body weight; body weight to the power of 0.75 isoften used to estimate metabolically active tissue.metabolism The processes of interconversion of chemical compoundsin the body. Anabolism is the process of forming largerand more complex compounds, commonly linked to the utilisationof metabolic energy. Catabolism is the process of breakingdown larger molecules to smaller ones, commonly oxidationreactions linked to release of energy.metabolomics Measurement of all the small molecules (metabolites)present in the organism, which represent interactions of thegenome, transcriptome and proteome with the environment. Seealso proteomics; transcriptomics.metabonomics Alternative term for metabolomics.metallisation See metallised films.metallised films For food packaging, manufactured by applyingvery thin layers of aluminium to a plastic film by vacuum deposition,to improve the barrier properties of the plastic. The thicknessof the metal deposit is generally expressed as percentagelight transmission through the film.metalloproteins Proteins containing a metal. For example,haemoglobin, cytochromes, peroxidase, ferritin and siderophilinall contain iron; many enzymes contain copper, manganese orzinc as a prosthetic group.metallothionein A small protein (M r 6800, 61 amino acids) thatbinds zinc, copper and cadmium. Important in both absorptionand metabolism of essential metal ions, and also sequestrationand excretion of metals such as cadmium. Plasma concentrationmay provide an index of zinc status.