Are Starchy Foods Needed for a Healthy Diet?

Ruth Buttigieg, BSC (Hons), MSc, ANutr is a qualified nutritionist who works at Natural Ketosis, where she helps people to better their health by changing their diet and lifestyle by following a low sugar low starch approach. Ruth read biochemistry for her undergraduate degree and she also has a Masters in Public Health Nutrition from Queen Margaret University. Here she blogs for us on a question that often comes up when it comes to diabetes and nutrition – are starchy foods really needed for a healthy diet?

We are constantly being told that foods such as bread, pasta, rice, potatoes and cereals are required for a healthy diet as they are full of nutrients. However, does their nutrient density outweigh their impact on our blood sugar levels and, in turn, on our health?

With more people being diagnosed with diabetes or diagnosed as pre-diabetic, the message of prevention is better than cure is a constant headline in the media. What else needs to be done to improve the nation’s health? What else can people do to change their lifestyles and improve their health? Our food choices are not immune to this spotlight.

Turning to the NHS for guidance, one meets with the constant message that starchy foods are an essential part of a healthy diet. With the debate heating up about which food item is public health enemy number 1 – fat or sugar, in this piece we explore why starchy food items aren’t needed for a healthy diet and in fact substituting these items for other vegetables will have a positive impact on your health.

Starchy Foods – What Are They?

Food items in this category can be broadly classified as fitting into the following categories: breads, pastas, rice, cereals and grains. These food groups are also commonly referred to as complex carbohydrates.

Complex carbohydrates are a series of glucose (sugar) molecules linked together in a long chain. Once in the gut, our digestive enzymes break these links, thereby releasing individual glucose molecules. These molecules are then absorbed into your bloodstream and have a direct impact on your blood sugar levels, which in turn causes a spike in insulin levels.

How do you know a food’s impact on your blood sugars?

The effect that individual food items have on our blood sugars are measured using the Glycaemic Index (GI).  Whilst the amount of total carbohydrate in a food item (from the food label or from the using national databases such as McCance & Widdowson for the UK and the FDA in the USA) will give a good indication, i.e. the higher the carbohydrate content, the greater the impact on your blood sugars.

However, some items can be misleading. For example, 100g of potatoes contains around 17.2g of total carbohydrate – a reasonable amount some would say. But it has a GI reading, when baked, of 69 (with the skin) and 98 (without the skin). Table sugar has a GI of 58.

How’s that for a shocker?!

The glycemic index (GI)* is a ranking of carbohydrates on a scale from 0 to 100 according to the extent that they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels.

However, just because table sugar has a lower GI than potatoes, that does not mean a free reign to start adding sugar to your tea! What this shows is that carbohydrates are not all created equal and that starchy carbohydrates do still have a very immediate impact on blood sugar levels.

So what’s the final verdict?

Minimising sugars in the diet is always a positive idea and your body will thank you for it. However, starchy carbohydrates will still have a negative impact on blood sugar levels as starches are linked sugar molecules. Hence, once digested, starch will have the same impact as granulated sugar does on blood sugar levels.

The science and personal testimonies all show that specifically following a lifestyle that is low in simple and starchy carbohydrates actively helps to successfully manage diabetes through diet.

Focusing on fruit and vegetables that are naturally higher in dietary fibre will help to ensure that you are meeting all the vitamin and mineral requirements for optimal health, but without compromising your blood sugar levels in the process.

*For more information on Gl, please visit the official website of the glycaemic index. Pic thanks to Wikipedia.