To provide a colloidal low-calorie food material having excellent heat-reversible stability and capable of being stored and distributed. A method (10A) for manufacturing a colloidal low-calorie food material, characterized in having: a first step (step S01) for stirring water (2), glucomannan or refined arum root flour or a combination thereof (3), and a dissolution resistant absorbent (4), and thereafter allowing the mixture to swell to prepare a colloidal substance (6)； a second step (step S02) for mixing an alkali agent (5) into the colloidal substance (6) to prepare a pH-adjusted colloidal substance (7)； a third step (step S03) for heating the pH adjusted colloidal substance (7) under temperature conditions of 70 to 130 DEG C to produce a gelatinous substance (8)； and a fourth step (step S04) for cooling the gelatinous substance (8) to a temperature zone of 0 to 15 DEG C to form a colloid.本發明的課題為提供一種熱可逆性的穩定性優良，可保存或流通之溶膠狀低熱量食品原料。本發明的解決手段是透過如下:一種溶膠狀低熱量食品原料的製造方法(10A)，其特徵包含:使水(2)，與聚葡甘露糖或蒟蒻精粉或聚葡甘露糖、蒟蒻精粉的組合(3)，與難溶解性吸水劑(4)攪拌後，使其膨潤並調製溶膠狀物質(6)之第一程序(步驟S01)；將鹼劑(5)混練於溶膠狀物質(6)，調製pH調整完了溶膠狀物質(7)之第二程序(步驟S02)；在70-130℃的溫度條件下將pH調整完了溶膠狀物質(7)加熱並製作凝膠狀物質(8)之第三程序(步驟S03)；以及將該凝膠狀物質(8)冷卻到0-15℃的溫度區域並使其溶膠化之第四程序(步驟S04)。
