If you are training regularly but also trying to lose weight, it is important to eat the right type of snacks both before and after your workout. This article provides an explanation of how the body uses carbs and fats for fuel during training and how this can be used to aid weight loss, plus some snack suggestions to try before a workout.
When exercising the body uses two main sources of fuel, namely carbohydrates and fats. Carbohydrates come from foods consumed containing sugars and starches, and from glycogen (stored muscle and liver energy). Glycogen is the body’s preferred source of fuel (especially during high intensity exercise) as it is more readily available.
When the focus is on performance rather than weight loss, glycogen stores are the limiting factor. As when glycogen reserves are depleted through prolonged intense exercise, the body then switches from using carbohydrate to fats for fuel and performance decreases.
However this is an advantage when weight loss is the goal, as fat is utilised rather than stored when the glycogen reserve runs out. Fat comes from triglycerides and free fatty acids in the blood as well as stored fat. Also during lower intensity exercise the body can use fat for energy more effectively than during high intensity exercise.
When fat is used as fuel this can help decrease body fat, makes the body more sensitive to insulin as well as other benefits such as better repair and increased immunity.
Sometimes people try exercising on an empty stomach (such as skipping breakfast) as they believe it will help with weight loss. However this has been shown to decrease the intensity and quality of training, so in my opinion is not considered a good fat-burning strategy for most people.
Likewise, if the wrong types of snack are eaten prior to working out, the process of switching to fat-burning becomes less effective. Foods that are high in simple carbohydrates (i.e. biscuits, cakes, confectionary, fizzy/isotonic drinks etc.) provide the wrong type of fuel as they make it more difficult to deplete stored glycogen and to move into fat burning mode to aid weight loss.
Eating foods containing slow-releasing complex carbs and protein will help to shift the body from using carbs for fuel to being more effective at fat burning (gluconeogenesis).
Research shows that consuming snacks (ideally 2 hours before your work-out) that are low in fructose and low glycaemic index foods which allow a slow release of energy in the bloodstream, will allow you to go a little longer and harder in your workout.
So what are good pre-workout snacks that provide energy and nutrients but also allow you to burn fat?
Some tasty snack options include:
– A small handful of almonds/walnuts and an apple.
– Vegetable crudités and humus.
– Oat cakes/rice cakes spread with cashew/almond nut butter.
– A boiled egg and a slice of wholegrain toast.
– Porridge oats, made with almond/oat/rice milk sprinkled with mixed seeds and berries.
– A protein shake made with 1/2 cup of coffee, 1/2 cup of coconut milk and one scoop of chocolate or vanilla protein powder
– Unsweetened Greek yogurt/ live organic yogurt and berries
In addition certain nutrients belong to a group that mimic the effects on the body of exercising in a fasted state. These are called stress-activated food nutrients (SAF) i.e. phenols, caffeine, theobromine, catechins, and immune proteins. Foods containing high levels of SAF nutrients include: coffee, cocoa, green tea, and pasture raised grass-fed whey. Therefore these nutrients may be also useful if incorporated in