My most repeated advice in clinic is balance your blood sugar by cutting out sugars. It can give you stable energy levels and help you lose weight.
Sugars are a type of carbohydrate and are divided into groups depending upon their structure. Glucose is one of the simplest sugars and is what the body breaks down all sugars and carbohydrates into for use as its main energy source. The brain and muscles mostly use glucose but carbohydrates aren’t essential as the body can make glucose from fat or protein.
Some carbohydrates, simple sugars and refined carbohydrate, are broken down very quickly and give a fast energy release. They don’t all taste sweet and include white rice or bread as well as cakes, sweets, honey, fruits & juice. Others like wholegrain carbohydrates, pulses, vegetables are more slowly broken down because of their complex structure. Think of this as paper versus a wood log on a fire. Paper burns quickly but for a short time whereas wood burns slowly for longer. You may have heard the term glycaemic index which refers to how quickly a carbohydrate will increase blood glucose. It was originally used as a measure to help diabetics control their diet. It’s not that simple though, aside from learning the index for foods, you need to consider the amount of the food you eat and also what you eat it with.
Insulin - the ‘fattening’ hormone
The body keeps blood glucose levels tightly controlled and releases the hormone insulin to escort it into the cells. In cells glucose is burned (oxidised) immediately for energy or what isn’t needed is stored as glucose (it can only do this for small amounts), or more likely as fat. Insulin also reduces fat breakdown (lipolysis) by blocking the activation of an enzyme that triggers lipolysis (1). It is not just fat that can make you fat. I get annoyed when I see ‘fat free’ on sweet foods (sweets, meringues, jelly) because it doesn’t mean the food won’t cause weight (fat) gain.
Also high carbohydrate diets (many conventional weight loss diets are low fat higher carbohydrate) can raise triglycerides and lower HDL (‘good’) cholesterol levels in the blood, which are linked with heart disease and stroke risk (cardiovascular disease) (2). And this is more likely with simple carbohydrates rather than complex carbohydrates (those with higher fibre and wholegrain).
Look for the "Carbohydrates (of which sugars)" figure in the nutrition label, below 5g/100g is considered low sugar. Fruit juices, smoothies, dried fruit and tinned fruits are not low sugar. Few whole fruits are below 5g/100g of sugar (some berries) but you benefit from fibre and other nutrients and it is more difficult to eat large quantities of whole fruits.
Tip: Look at labels on yogurts, breakfast cereals, drinks including fruit juice, and cereal bars. People think to restrict cakes, biscuits and confectionery when cutting back on sugar but not these foods. They contain a lot more sugar per serving than you think, there are 16g in an Activia strawberry 125g yogurt, 10g in 4 Belvita breakfast biscuits and 16g in a portion of Jordans oat raisin Granola.
In the ingredients list look for sugar, syrup and words ending in ‘ose’ (maltose, fructose, glucose) to give you an idea of the added sugar, and the higher up the ingredients list the greater the quantity in the food. If the sugar is a natural part of the food (for example in plain yogurt, sweetcorn, fruit juice) the sugar inside the food obviously won’t be listed as a separate ingredient but will still show as sugars in the percentage nutritional breakdown.
The key is to cut back on simple sugars and refined carbohydrate. These are sugars and ‘white’ grains in cakes/pastries, confectionery, alcohol (yes alcohol too!), fruit juice, white bread and rice. Eat sugars as wholegrain carbohydrates (oats, brown rice, wholewheat), pulses, vegetables and whole fruits. These are more slowly broken down providing stable energy and nutrients, they fill you up and help manage a healthy weight.
In part 2 of the blog I’ll list what I ate on my low-sugar day, give some guidelines and food swap suggestions.
1. Zhang J, Hupfeld C, Taylor S, Olefsky J & Tsien R (2005). Insulin disrupts b-adrenergic signalling to protein kinase A in adipocytes. Nature. 437:p569-573
2. Hudgins L, Hellerstein M, Seidman C, Neese R, Tremaroli J & Hirsch J (2000). Relationship between carbohydrate-induced hypertriglyceridemia and fatty acid synthesis in lean and obese subjects. The Journal of Lipid Research. 41:p595-604