Let’s try and keep things simple. Many diets have sprung up and continue to be popular by banishing carbs altogether. The problem occurs when we eat refined carbs (think white bread, white rice, white pasta) which all have the potential to be broken down into sugar causing a rapid spike in blood sugar levels. Their effect is very similar to that of eating normal sugar.
What determines with carbs how quickly this breakdown occurs is…
1. Processing (eg removal of fibre)
2. The amount of cooking
3. What it’s eaten with.
Processing to remove fibre e.g white rice, white pasta or white bread speeds up digestion and subsequent conversion to sugar. Cooking also increases the speed of digestion, so salad and raw veg release sugar more slowly than boiled, steamed or baked veg. The release of sugar from carbs can be slowed down by including protein and/or fats in the meal.
When we look at some of the basic problems we face both in terms of how we feel on a daily basis and what diseases manifest over time we can find many links with sugar (and also refined carbohydrates). This is more to do with hidden sugars in the form of high fructose corn syrup than sugar found in your average potato. For the record I’m not anti carb and the body needs them but most often the importance is in the timing and the quality of the carbs you are consuming. When I talk about quality probably the best way to address the quality of a carbohydrate is how quickly it effects blood sugar levels. The best way to look at this is by using the G.I or Glycaemic Index of foods. The lower the GI the longer it takes to digest and the lesser the effect on blood sugar levels.
Whenever we eat any form of sugar it causes a rise in blood sugar levels. In response to this the body releases insulin to bring blood sugar levels back down. Importantly insulin is also a storage hormone and will shuttle glucose either into the liver or the muscles for energy or fat cells for storage. It also shuttles fatty acids into the adipose tissue to be stored as fat and blocks fat burning.
What we want to avoid is a yoyo effect (sharp rise after eating for example a mars bar which is followed by a crash causing hunger, irritability and mood swings) in blood sugar levels. Ideally, we want to keep the rise and drop in blood sugar as “flat” as possible. We achieve this by eating more complex carbs (lower GI) that don’t create such a rapid rise in blood sugar levels and / or by combining carbs with quality proteins and fats to slow down speed at which carbs enter the system.
With stable blood sugar levels comes stable insulin which in turn means you can start to burn more of your stored fat for energy.
Examples of carbs to avoid:
The following carbs are heavily refined which makes them digest in exactly the same way as simple sugars. In fact, depending on the cooking method some forms of white rice digest FASTER than glucose….
The majority of breakfast cereals,
rice cakes etc.
Whist it’s a good idea to cut refined carbs and sugar out of your diet it doesn’t mean that all “white” carbs need always be avoided. There is a time and a place for everything.
For example, we can harness the effects of insulin by eating refined carbs together with protein post training to promote muscle repair and start the rebuilding process. If your motivation is to increase muscle, eating refined carbs and protein post workout provides the perfect environment to increase protein synthesis. The subsequent spike in insulin levels ensures glucose and protein gets shuttled to where it’s needed. Glucose to refuel the muscles and protein to start the above mentioned repair / rebuild process. Muscles act like a sponge after a workout. We just need to give them what they need.
So, if you want to indulge in some of the “white” carbs the best time is after a workout!
I work on this premise when eating carbs: It comes down to timing and how much I’m training.
If I’m training a lot I know I’ll need to give my body what it needs to repair and refuel itself which means I’ll plan to eat more in the way of carbs especially after my training when they’ll be used most efficiently. If I’m planning a day off I’ll completely cut out any refined carbs, stick to more protein, quality fats with more in the way of vegetables.
If I plan on training in the morning and my workout is more cardio based I tend to have a coffee and water beforehand and after the workout have breakfast combining a variety of carbs with a good source of protein such as eggs, whey, meat or fish.
If I’m not working out I’ll either have a breakfast based around a slow releasing carb source such as oats [click here for my preferred breakfast option] to provide a sustained release of energy over a longer period of time (not spiking insulin levels) or stick to a more protein based breakfast. My body at this point just doesn’t need simple carbs.
What are complex carbs and what are the better choices?
Oatmeal (look for steel cut)
Brown basmalti long grain rice*
Pumpkin and other root vegetables
100% whole grain breads or pastas
Beans and lentils
Potatoes with skins on (potatoes score a high GI value so it’s important to eat them with protein and fats)
Vegetables are also a good source of complex carbs (raw veg digests slower than cooked) and fibre as well as a host of other necessary nutrients. If you are on a business trip and you want to minimise the extra pounds client dinners seem to be adding to the waist line, try and replace pastas and rice with more vegetables. You’ll still be getting carbs but with added fibre which keeps you feeling fuller for longer as well as other quality nutrients. Here are some examples:
Salads – as many colours as possible – This even with the addition of dressings provides a very good low GI meal.
Peppers – all colours
In the 1970’s, believing fats were the devil, causing heart disease, obesity etc many fats (that made you feel fuller for longer) were replaced by sugar (causing blood sugar levels yoyoing all over the place) It is now recognised this was based on some pretty flawed science as obesity levels exploded and heart disease went through the roof.
To sum up, what makes people fat is eating refined carbs (sugar, white rice, white pasta, white bread etc) and high fat foods eg cheese at the wrong time of day. So eating the bread and a cheeseboard after a meal is the fastest route to getting fat.
*The GI (Glycemic Index) is a measurement of how quickly a particular sugar will enter the bloodstream. Potatoes and white rice score quite highly on this chart but if they are mixed with fats and proteins their effect on blood sugar levels is blunted. So, olive or avocado oil on the rice together with tuna would not spike insulin levels in the same way as a plate of white rice on its own.