Observations and investigations were carried out on 50 patients with diabetes of mature years and light obesity of nutritional-metabolic type in a moderately high mountain (1870 m above sea level). After 20-day treatment, including daily, lasting physical loadings, cool sun-air exposures and moderately reducing diet of 1600-1800 kcal, a clinically significant reduction of a wide range 6,699-7,537 MJ = of lipid indices was established, namely--total fats, total cholesterol, beta lipoproteins, triglycerides, esterified fatty acids and lipoproteins with low density (LDL-cholesterol), an average with 9.3 to 19.5 per cent. A more pronounced reduction of lipid indices was established with higher initial values and moderate weight reduction with 3.5 kg for a 20-day treatment course. The physical loadings and cool sun-air exposure stimulated the lipolysis, the elevated levels of free fatty acids being chiefly used for energy supply of organism. The enhanced lipolysis was, very, likely, of essential significance for the favourable effect of hyperlipidemia.