Background
Evidence describing a relation between potatoes consumption and health or disease development is still uncertain. Epidemiological studies have reported conflicting associations between the intake of potatoes and the risk to develop type II diabetes (T2DM) and cardiovascular diseases (CVD). A limitation of these epidemiological studies is the lack of differentiation by the type of potatoes consumed and the preparation method. Fried potatoes are associated with weight gain and developing T2DM, while non-fried potatoes seem not associated with cardiometabolic risk. In a few randomized controlled trials, no adverse effect on cardiometabolic health was found after non-fried potato consumption. However, these trials were either short-term interventions or examined potatoes with a high phenolic load that are not representative of potatoes typically consumed. Therefore, it is still difficult to conclude whether potatoes, which are a staple food in most northern European countries and are typically consumed several times a week, should be recommended or not.

Objective
The LoPoCardio trial compares the effects of longer-term consumption of a potato-based carbohydrate-rich food pattern versus a pasta and rice-based carbohydrate-rich food pattern on cardiometabolic health. The primary outcome of this study is to assess a change in average daily glucose concentration for three consecutive days. Additionally, a pre-and post-intervention postprandial test will assess postprandial glucose and triacylglycerol responses.

Methods
The LoPoCardio trial has a randomized parallel design including 56 overweight and obese (BMI 25-35 kg/m²) participants. During the 12-week intervention, 28 subjects will be assigned to consume 150 g of boiled potatoes daily, while the other 28 subjects will consume an iso-energetic amount of white rice and white pasta. The primary outcome will be calculated based on the total area under the curve (tAUC) over the entire 15 hours follow-up (7:00 AM – 10:00 PM) in glucose monitoring during these three days.