T t

aldolase aldolase glyceraldehyde di-hydroxyacetone-P '

• glyceraldehyde 3-P

triose-P-isomerase glycerol-3-P-dehydrogenase triokinase

glycerol-3-P

glycerol-3-P acyltransferase pyruvate lactate pyruvate dehydrogenase acetyl CoA

acetyl-CoA carboxylase

acyl glycerols acyl CoA —malonyl-CoA-

VLDL NEFA |Nvket?ne

' bodies citrate cycle

carbon dioxide

Figure 3 The monosaccharide products of sucrose digestion are metabolized to carbon dioxide and water via the tricarboxylic acid (TCA) cycle. From Southgate D (1995) Digestion and metabolism of sugars. American Journal of Clinical Nutrition 62: 203S-211S.

liver to fructose-1-phosphate, which is spilt into two C3 products, glyceraldehyde and dihydroxacetone phosphate. The latter is an intermediate for both the glycolytic and gluconeogenic pathways. The glyceraldehyde is phosphorylated and recombines with dihydroxyacetone phosphate to produce fructose-diphosphate and ultimately glycogen. The major metabolic effect of fructose is to increase the production of pyruvate and lactate. This has the effect of depressing fatty acid oxidation and increasing the esterification and the synthesis of very low-density lipoprotein (VLDL). There is only a small rise in plasma glucose (and insulin) levels because gluconeogenesis is strongly inhibited. A rise in plasma lactate is seen after fructose consumption.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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