Low Carb Diets:
Pros, cons and possible applications for fat loss, muscle gain and strength development.
If you compare a low carbohydrate diet to a medium carbohydrate diet, fat loss will be the same for most people when total calories consumed are matched.
However, strictly limiting carbohydrate intake may be a viable and effective option for individuals that do not want to count calories or adhere to a rigid diet. Simply limiting carbohydrates whilst consuming mainly protein and fat rich foods (as well as green vegetables) for most people will result in a caloric deficit, whilst still allowing them to stick to a diet that provides them with sufficient protein and fat intake. There is also research that states that low carbohydrate diets help to manage and suppress hunger, though this is dependant on the individuals response.
With that said, in my opinion the vast majority of people seeking fat loss will be best served by adhering to a sustainable diet, for most people a zero to low carb diet just isn’t sustainable.
Muscle and Strength Development:
Typical muscle and strength building workouts will rely heavily on glycogen (the bodies form of stored carbohydrate). Compared to fat, carbohydrates are a much more efficient and preferred source of fuel, part of the reason for this is that glycogen is stored in the muscles and so is readily available to supply energy. Whereas fat must go through a longer conversion process before it can be used as fuel. In fact, it has been shown that glycogen stores can be depleted by as much as 30-40% locally (within the specific muscles used) after a hard weight training workout.
Most people that are prioritising muscle or strength development should not go below 1-2g of carbohydrates per kg of bodyweight to ensure that these stores are replenished adequately.
However, low carbohydrate diets may be a viable option for strength athletes in certain circumstances including:
-During a peaking phase for weightlifting or powerlifting where the reps performed will be less than 3 and overall session volume (total sets and reps) is low, ATP, rather than glycogen will be the main fuel source used. During this phase a reduction in carbohydrates generally will not have a significant impact on performance, and the glycogen depletion alone will reduce bodyweight by several kilos which may be the goal for some athletes during this phase.
-If when gaining muscle minimising body fat gain is important, low carbohydrate intake may be an effective strategy on days off from training where the need for carbohydrates will be hugely reduced.
I trialled an extremely low carbohydrate diet for 10 weeks. During that time I experienced:
-Rapid fat loss, without significant loss of strength or muscle for the first 6 weeks. After which point fat loss decreased and my physique generally deteriorated.
-Reduction in mood. This is generally in line with research, as reduction in mood is common on low carbohydrate dieting. However, some individuals report increased mental clarity and concentration.
As with most things training and nutrition there will always be individual differences and outliers, but for the vast majority of people I do not think that low carbohydrate diets are optimal.