Is carb cycling better than linear dieting?

It's a reasonable question, but also one that individuals rarely tend to take the time to think through. To weigh up the pro’s and con’s for their particular, personal situation. There’s no question that carb cycling can work. It can and does. In the right circumstances carb cycling can have a major impact on an individual’s overall diet experience. But so to can linear dieting.

For starters, by linear dieting I mean standard dieting: maintaining the same calorie and macronutrient plans each day. Carb cycling is therefore a non-linear strategy. While there is a abundance of anecdotal evidence available, from individuals who have found success with carb cycling, however from my knowledge, there is a severe lack of controlled studies comparing linear dieting to carb or calorie cycling.

What this means is that we can only really consider the possibilities, weigh up the pro’s and con’s and then make an educated decision based on your individual situation.

To help you guide that educated decision I’ve done most of the hard work for you and outlined some of the major considerations when deciding whether or not you should consider implementing it a carb cycling approach.

PROS:

Maintain or increase training intensity

Depending on your default diet, higher carb intake equates to fuller glycogen stores. Ensuring that you have high carb availability (full fuel stores) around training sessions may increase or maintain training intensity thereby leading to muscle/strength gains or maintenance when dieting. As a side-note to this, if you’re someone who trains early in the morning then it may be worth placing a significant portion of your carbs at dinner the night before to utilise the increased glycogen stores.

Potentially improves individual’s metabolic flexibility

Metabolic flexibility refers to an individual’s ability to switch between using glucose and fat for fuel. By cycling carb intake between high and low days we can potentially improve metabolic flexibility by training the body to fuel itself in low and high carbohydrate environments. Sitting around the office all day with no intense exercise planned? Metabolic flexibility means you can efficiently mobilise and then use fat for fuel on your lower carb days.

Increased Diet Adherence

Dieting for long periods of time can straight up suck. At some point, carbs are likely going to take a hit (because nobody enjoys the sex drive-killer that is a super low-fat diet and we all know the benefits of protein). Following a carb cycling protocol that has lower and higher days may help break up the monotony of dieting and allow some higher carb foods that may typically be restricted on a normal diet. This psychological break may lead to better long term adherence which is a key factor.

Increased Anabolic environment at key times

Essentially when dieting we are going to see the body spending more time in a catabolic state, and less time in an anabolic state. A large part of this is due to reduced levels of insulin which is a key anabolic hormone in the body due to it’s ability to suppress muscle protein breakdown.

Dieting induces lower insulin levels (especially on a lowered carbohydrate intake), and is likely to place us in an overall net state of catabolism. This is not necessarily a bad thing as you need to be catabolic to optimally release fat and oxidise it.

At the end of the day, whether we build, lose or maintain muscle comes down to protein balance over time. That is, whether we spend more time in positive protein balance or negative balance. Too often people focus on muscle protein synthesis (MPS) and forget about the other side of the equation that is muscle protein breakdown (MPB). Both impact daily net protein balance and should be considered. Higher carb days will increase insulin levels, reduce MPB and thereby increase overall anabolism and protein accretion. Timing this with training may improve body composition.

Some pretty impressive looking positives. However, you’ll have noticed that I used the words potentially and may quite liberally throughout. These aren’t set in stone, just theories.

On the other side of the coin we could also argue that there are potential negatives to consider.

CONS:

Simple is often Best

Following complicated protocols can be fun and exciting. It can also increase the amount of energy, time and willpower you have to invest in the protocol. We have to weigh up the potential ROI (return on investment) of whatever strategies we put in place and decide whether they are going to be beneficial or a burden. As I mentioned previously, adherence and consistency are paramount when dieting. Anything that may put those at jeopardy are often not worth the small benefits they may offer.

Having macros and/or meal plans that change and switch often can make things too complicated and increase stress for some individuals. Carb cycling can work for some by increasing adherence and consistency, but have the opposite effect in others.

Fluctuations in Progression markers

Wavering carb intake can lead to fluctuations in a number of markers that we use to monitor progression over time. Glycogen stores, water retention, food volume, electrolyte ratios can all affect scale weight, body measurements and appearance which can make accurate progression appraisal difficult, especially for those who are unsure of what to look for.

Again, I’ve seen more then enough people stress themselves out over fluctuations in weight and appearance to warrant this point. Recovery and exercise adaptions don’t just occur on the day of training.

While it makes sense to place carbs around training for optimal performance and recovery, it’s also worth noting that recovery and exercise adaptions are not contained to the immediate peri-workout period, rather the adaptive process is continual. Dropping carbs and calories too low on subsequent days may affect this process.

An increase in Cravings

I’ve often seen high carb days, especially if utilising a once a week re-feed, take a similar shape to cheat meals. That is, often individuals will decide to indulge in highly palatable foods they’ve been avoiding while dieting. While for some this is fine and can even be beneficial, for many, indulging in hyper-palatable foods can often have the negative effect of increasing cravings for more of these foods making a dieting process harder then necessary.

Wrapping Up

While I’m of the opinion that carb cycling can be a useful tool, having successfully utilised it with both myself and clients, it’s important to realise that as with most tools there is a time and place that it should be used.

In terms of actual practical differences in body composition, it's near impossible to give a concrete answer based on what studies have currently been done.

In my opinion if we were to keep ALL other variables the same (energy expenditure, training performance, calorie intake, weekly total carb intake, sleep, stress, etc.) I’m doubtful we'd see any difference whether someone hit a consistent carb intake everyday, versus cycling up and down.

However, it is possible there may be a difference if carb cycling causes one or more of those variables listed to change, and I think there is a high probability that this may occur in some people.

For the majority of individuals, carb cycling isn’t going to be necessary and may actually be detrimental via making the diet more complicated which can lead to decreased adherence and consistency. In the grand scheme of nutrition and body composition, nutrient timing and/or carb cycling appear to be a small rock relative to the total energy intake, macronutrient amounts and nutrient density boulders that form the foundations of a good diet.

Ensure that you have the foundations in place before building upon them with the smaller, more intricate details that, while important, don’t have the same ROI. Decide what is going to make YOUR diet as easy to follow as possible. Rather then trying to fit your lifestyle and preferences to a particular diet, why not mould the diet around your lifestyle and preferences? I guarantee you will find it easier to maintain and see better results.