2.3. Study Diet—The KoALA Concept
After one week of the preliminary phase, each participant was randomly assigned to one of the four groups. The intervention phase of the study ranged over 12 weeks for each participant. Visits to the study center took place at baseline and after 4, 8, and 12 weeks, to take samples, provide study materials and solve potential problems owing to the implementation of the menu plans (The daily intake of linseed oil constituted 27 mL for men and 22 mL for women. This dosage corresponds to around 10% of the daily energy intake (en%). In addition, the HLA, LLA, and MF groups received defined menu plans for each study day to modify the background diet and homogenize the energy intake. Participants in the control group were asked to maintain a typical Western diet (without menu plans). They also consumed the pre-defined amount of linseed oil.For the HLA group, the menu plans ensured an additional 20% of daily energy intake via fat which consisted of 7 ± 2 en% LA, up to 10 en% saturated fatty acids (SFA) and 3 ± 2 en% MUFA. The menu plans included oils rich in For the LLA group, the additional 20 en% of fat consisted of below 2.5 en% LA, at least 15 en% MUFA provided by olive oil and nuts such as almond, cashew, and hazelnut plus around 2.5 en% of SFA.For the MF group, the additional 20 en% of fat mainly was provided by milk fat from milk and dairy products (15 ± 2 en%) plus 5 ± 2 en% SFA, MUFA, and All menu plans provided 2500 calories for men and 2000 for women, split into 55 en% of carbohydrates, 15 en% of protein, and 30 en% of fat. In addition, the menu plans were characterized by the following criteria:Absence of other foods providing Reduced intake of monosaccharides and increased intake of dietary fiber.Reduction in salt.Increased consumption of fruits and vegetables.Reduction in foods which are highly processed, calorie-rich, and low in nutrients, such as fast food and convenience products.The menu plans included up to five meals per day split into breakfast, lunch, dinner, and up to two snacks. For each meal, detailed information on the type and amount of the food was provided. Recipes for meals that required preparation were also included.To increase compliance, linseed oil was provided to each participant. The fatty acid distribution for the linseed oil is shown in 