METABOLIZABLE ENERGY OF HIGH NONSTARCH POLYSACCHARIDE-MAINTENANCE ANDWEIGHT-REDUCING DIETS IN MEN - EXPERIMENTAL APPRAISAL OF ASSESSMENT SYSTEMS

We have examined the reliability of several food energy assessment sys tems for healthy men. The predictions of metabolizable energies were c ompared with determinations made in energy balance studies with three maintenance diets (12 MJ/d) one of the diets was moderate in non-starc h polysaccharide (NSP; 2.1% of gross energy) and two were higher In NS P (3.5-4.6% of gross energy). A fourth diet was a submaintenance (6 MJ /d) high NSP (7% gross energy) diet. Discrepancies between the differe nt food energy assessment systems and the determined metabolizable ene rgy values ranged between 0 and 15%. With the maintenance diets, the A twater specific factor system had errors generally within 6% of the de termined value and a limit of agreement (bias +2sD) for diets of 10%. This accuracy compares with errors of 2% for both the originally publi shed assessment of this system and a more recent general formula; both systems were without bias with increasing NSP content of the diets bu t the latter had limits of agreement within 3%. In contrast, the Atwat er general, the European general and a recent FDA general formula show ed increasing bias with increasing NSP intake. All of the general ener gy assessment systems overpredicted metabolizable energy from the high NSP submaintenance diet, which shows that even the least biased and m ost reliable energy assessment system that we identified applies to ma intenance diets only; thus a correction has to be made for submaintena nce diets.