Don't Obsess Over Cutting Carbs
Low carb diets can be effective, but they can also be disastrous when starting your body recomposition journey
Last week’s article discussed the benefit of focussing on a single macronutrient and tracking its intake in line with your goals. It’s a simple and effective way to improve macronutrient intake without overwhelm in the early stages of nutrition optimisation.
Today I want to focus on the downside of the opposite strategy - heavily restricting the intake of a macronutrient, specifically carbohydrates. Theoretically, this approach can sound good but rarely feeds into long-term adherence, a critical component of successful body recomposition strategies.
Until the mid-2000s, fat was the villainous macronutrient to avoid in most popular diets. Low-fat and fat-free product lines were all the rage, often relying on added sugars for palatability.
Over the past 20 years, there has been a switch and carbohydrate has swung out of favour. Sugar and carbohydrate intake has been supposedly associated with everything from increased rates of overweight and obesity to reduced attention spans.
The truth lies somewhere in the middle; both macronutrients play essential roles in our bodies and require daily consumption. Excessive intake of either can lead to problems, especially overweight and obesity, but this is because they contribute to an energy surplus.
Plenty of people doing high amounts of physical activity consume large intakes of fat or carbohydrate without weight gain because their energy expenditure matches energy intake.
So let’s see why excessive carbohydrate restriction is a bad path for many people starting their body recomposition journey.
Short term gains can trick you
Early wins significantly impact people’s perceptions of a strategy and restricting carbohydrate intake can leverage this.
The body stores carbohydrates in the form of glycogen, which is a protein unit with multiple glucose units attached. The body contains roughly 400-600g of glycogen in the muscles and liver.
Each gram of glycogen is stored alongside 3-4g of water. This means 500g of glycogen also has another 1500-2000g of water associated with it, for a total weight of 2000-2500g.
When carbohydrate intake is restricted, glycogen stores are released for use but not replaced. This leads to a loss of total body mass through glycogen, which is burned for fuel, and water, which is released back into the bloodstream and excess is excreted as urine.
If glycogen drops by 400g, there will be a total weight loss of 1600g (400g glycogen + 1200g water). This is easy to achieve over a week of restricted carbohydrate intake.
If you get on the scales at the end of your first week and see a weight loss of 1.6kg, you will be happy with that result. However, this change in body weight reflects glycogen and water only, not necessarily a change in body fat.
It’s common for people to lose body fat while restricting carbohydrate intake because they also create an energy deficit. This leads to additional changes in body weight, but again, the loss of glycogen and water inflates the lost body fat.
The glycogen and water trick cannot be repeated. However, so long as carbohydrate intake remains low and glycogen stores are not refilled, the weight will not return. But this tends not to be adhereable for the long term.
Low carb = low intensity
Glucose from carbohydrate or glycogen stores plays a key role in moderate-high intensity exercise. The oxidation of fatty acids cannot occur fast enough to meet fuel demands at these intensities, so performance will decrease if glucose is unavailable.
This can limit training intensity and the ability to create progressive overload in a training program, causing plateaus or regression in strength, fitness and performance.
Seeing results from training helps drive adherence to the body recomposition strategy because there are tangible benefits from the time and effort invested into the plan. These are especially important when body composition slows after a fast start.
Limiting strength and fitness adaptations can also cap future energy expenditure from physical activity. Getting stronger and fitter allows you to do more work for longer, increasing energy expenditure and achieving the target energy balance at higher energy intakes.
What goes down may come back up
Remember the 1.6g of weight loss simply from the loss of glycogen? It’s waiting to return as soon as carbohydrate intake increases and glycogen stores are refilled. This won’t happen if carbohydrate intake remains restricted, but it will occur as soon as it’s not.
For many people, this occurs after their first lapse in the diet. They might be four weeks in and their body weight has dropped 4kg during the plan. They are out for lunch with friends, have a glass of wine and decide to forgo the carbohydrate restriction for the time being and order the pizza.
They figure they have broken the carbohydrate rule the next day and will start again on Monday, but it’s pasta and bread for now. As the carbohydrate refills their glycogen stores, their body weight creeps up.
By the time they check in on the scales on Monday morning, their weight is up 1.6kg and their total progress over four weeks is now a loss of 2.4kg. While 2.4kg is a great progress for four weeks on a new strategy, the 40% reduction in weight loss from the weekend can make people feel like they have failed.
Where early wins play an important role in driving adherence, significant regressions can go the other way. Suddenly, the strategy seems less effective, adherence is reduced, the energy deficit is lost, and weight increases.
This can be overcome by understanding the impact of glycogen and water on body weight. However, the person or article that sells you on the rapid progress often neglects to mention it before you start.
Wrap up
Low carbohydrate nutrition strategies can be effective as an overall strategy to manage energy balance. My experience with clients has seen them successful with people doing less physical activity or with dietary preferences towards higher-fat foods.
While these clients used a low carbohydrate approach, most started with different strategies before settling on low carbohydrate after trial and error. For most people starting, a balanced macronutrient intake will best suit their needs and allow them a base for future changes.
I am impressed that you outlined well structured and good points in favor of long-term progressions, goals, and well, carbohydrates!
All of this is particularly true and intensified the moment people want to do specific and targeted training (for physical or sport related goals), as well as when anyone wants to be "just fit and health", but are moving quickly towards working out every single day (or more than once per day).
Finally: a fine explanation of the old-school "Yo-yo"-effect!
You are a fool. Go ahead, encourage people to become diabetic. How did I follow you? I will fix that.