Effects of health-promoting education on changes in eating habits, the resultant body weight loss, and maintenance of the acid-base equilibrium in obese women were studied. The corrected diet and 4 months of health-promoting education were found to result in a statistically significant reduction in the diet calorific value, a decrease in the intake of total protein (including animal protein), lipids (including saturated fatty acids), cholesterol, sucrose, and sodium. On the other hand, an increase in the intake of plant protein, starch, lactose, dietary fibre, vitamins E, B1, B2, PP, B6, and C as well as minerals (Ca, P, K, Zn, Cu, Mn), and liquids was recorded. Those changes were accompanied by a slow, but consistent, reduction in body weight (9.5+4 kg, 0.55+0.18 kg/week) as well as a decrease in the body mass index (BMI) (from 35.8+4.5 to 30.1+4.2) and WHR (from 0.85+0.04 to 0.80+0.05). Although the diets were very carefully composed, with a particular attention being paid to their alkalising potential, a slight reduction - within the normal range - of blood pH (from 7.390 to 7.361) and CO2 pressure (from 38.4 to 37.7 mm Hg) was recorded. In addition, a slight - but dropping below the normal level - decrease in the hydrocarbonate (HCO3-) concentration (from 22.6 to 20.8 mmol/L) and a statistically significant (P