Ever feel lethargic, foggy-headed or hazy during the working day?
Inconsistent and/or rapidly fluctuating blood sugar levels may often be to blame. Unless following an extremely low carbohydrate diet (i.e. a ketogenic diet = carbs 5% total of daily energy intake), our body and brains will rely on a molecule called glucose (a basic building block of carbohydrates) as a default energy source.
Once consumed, many carbohydrates will be broken down into glucose by enzymes within the mouth and GI tract and absorbed into the blood-stream via the small intestine. The rate and extent to which blood sugar is affected will depend on the structure of the carbohydrate (i.e. simple or complex), what it is accompanied by and the quantity consumed.
The glycaemic index value is a relative ranking of carbohydrates based upon how dramatically they will impact blood sugar levels. Generally speaking, the more complex and unprocessed a carbohydrate (e.g. fruits and veg), the more slowly it will be digested, absorbed and metabolised, resulting in a mildly elevated, stable blood sugar profile. Conversely, simpler, highly refined carbs such as white bread, sugary drinks and sweets will be absorbed rapidly, causing a sharp spike and dip in blood sugar, often leading to tiredness and the desire to reach for more foods to satisfy hunger pangs and counteract energy dips.
Not only can energy be affected, but given that our brains are completely reliant upon the glucose supplied by the blood-stream, wild fluctuations may also lead to disruptions to mental focus and mood. In fact, up to 25% of the glucose within the blood is directed toward the brain to fuel its neural activities, which considering its disproportionate size to the rest of the body, makes it a greedy little sugar muncher.
Choosing snacks and meals with low glycaemic values can be a helpful way to avoid the blood sugar rollercoaster and may practically be achieved by choosing good quality, whole foods which have been minimally processed. Starting the day with a good quality low GI breakfast (e.g. porridge) will also set us up well for the day and provide us with a sustained and gradual energy release and keep us on top form until lunchtime.