Maintaining strict meal timings and eating a balanced diet is the key advice doctors give to people with type 2 diabetes. This typically involves consuming low glycemic index (GI) meals, particularly at night, so that the patient's postprandial or post-meal blood sugar levels do not jump up. This is the reason that diabetes patients are ordered to stop heavy meals or meals consisting of white rice, potatoes, or sweets.
But a recent study published in Clinical Nutrition shows that GI is not the only factor to be taken into consideration when it comes to patients with diabetes and that it is not compulsory for them to eliminate potatoes either.
The researchers behind this research admit that their approach has major limitations. During meals, these carbs are rarely eaten in isolation and are most likely to be mixed with other ingredients. In this situation, the glycemic response (GR) to foods such as potatoes will depend on co-ingestion or other foods, the quality of their micronutrients, the preparation, and cooking methods, all of which may have a major effect on the resistant starch content. The resistant starch content of potatoes is also influenced by frequent cooling and reheating of carbs and can thus impact the GR. Finally, instead of relying on only the GI of specific foods, GR will also depend on the variability of the individual.
The researchers behind this study investigated the effect on the postprandial glycemic reaction of various cooking potato methods when eaten as part of a mid-evening meal. Additionally, in type 2 diabetes patients, the researchers determined the nocturnal GR and postprandial insulin response. To discover which has a worse postprandial and nocturnal GR, they compared many potato-based meals with low-GI basmati rice.
The study included 24 males and females with type 2 diabetes aged 58 years and older. A standardized breakfast and lunch were offered to the participants. At 6 pm, dinner was served and included boiled potatoes, roasted potatoes, and 24-hour cooled boiled potatoes or low-GI basmati rice. 50%carbohydrates, 30% fat, and 20% protein were contained in each meal. Prior to and directly after meals, blood samples from the participants were taken. They were also taken for the next 120 minutes at 30-minute intervals, and a glucose monitor was worn to test nocturnal GR.
The researchers observed that none of the potato meals resulted in a negative postprandial GR, even though a small increase resulted from the intake of the pre-cooked and reheated potato. In addition, the nocturnal GR was slightly lower than the amounts of those who ate low-GI basmati rice after eating potato-based meals.
Based on these reports, it is clear that for those who have type 2 diabetes, eliminating potatoes is not a requirement. Although freshly cooked, boiled, or roasted potatoes are considered to be better fit for those with diabetes, it is important to avoid consuming stale potatoes that need to be reheated.