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According to usual literature, the diet-dependent endogenous production of titratable acidity (TA) is contributed by sulphuric and phosphoric acids (NA) and by metabolizable acids (MAs), representing 'net-endogenous acid production' (NEAP). NEAP is mainly neutralised by diet-dependent [Formula: see text] salts of inorganic cations ([Formula: see text]), estimated in foods, faeces and urine from inorganic cation-anion difference (NB). It is claimed that urinary loss of organic acids' anions, '[Formula: see text]', induces metabolizable H+ ions' retention. Since '[Formula: see text]' is normally lost in urine as '[Formula: see text]' or '[Formula: see text]', no MA retention takes place. Therefore, in our approach, net acid production (NAP) reduces to endogenous sulphuric acidity only. Since in western diets (WDs) alkaline cations exceed inorganic anions (NB excess), acid excess from phosphorus is neutralized. Moreover, the renal reabsorption of ultra-filtered Pi takes place at [Formula: see text] ratios greater than '4/1', which means that the kidney operates as a dietary Pi-dependent NB generator ([Formula: see text] or [Formula: see text]). Since, in standard WDs, H2SO4 generation is less than '[Formula: see text]' production, the sulphuric acidity escaping the intestinal [Formula: see text] absorption is neutralized by [Formula: see text] and excreted as diet-dependent [Formula: see text], without interfering in normal A/B status. Only when extreme acidifying diets are ingested, sulphuric acidity may exceed '[Formula: see text]'. In this case, the excess of sulphuric acidity production is neutralised by the intervention of urinary [Formula: see text] excretion, whose employment is normally restricted to prevent loss of ultra-filtered NB. Finally, the whole body NA balance (NAb(W)) is calculated from the difference 'NAabs - NA(u)', where abs = intestinal absorption and u = urinary excretion. Being 'NAabs ≈ NA(u)', NAb(W) approximates zero, confirming WDs as non-acidifying foods.
PMID: 29186997 [PubMed - as supplied by publisher]