The Pros & Cons of Carbohydrates
by UP Fitness July 31, 2017
You hear ‘I don’t eat carbs’ a lot more often now than you would have done 20 years ago.
By many, it’s touted as the best or only way to burn fat. If you aren’t eating carbs, you must be burning fat for energy instead, right? Not necessarily.
Carbs (carbohydrates) are a hot topic right now, but they are sorely misunderstood, with a lot of confusion surrounding when and if to eat them.
Here we’re going to look at the pros and cons of limiting carbs. We’ll also explore which carbs might be best for you, when to consume them and how to use them to accelerate your results.
What are carbohydrates?
Carbohydrates are a collection of carbon, hydrogen and oxygen molecules. Because of their similar structure, sugars, starches and fibres all fall into this macronutrient category.
They are split into three groups based on how complex their structure is. Monosaccharides are the simplest, followed by oligosaccharides and finally polysaccharides.
The more complex the carbohydrate, the slower it will be broken down by your digestive system. Regardless of the speed of digestion, however, they will all eventually be broken down into glucose – the simplest form of carbohydrate. These can be bound together to form glycogen molecules which are primarily stored in muscle tissue and in the liver.
Foods with high carbohydrate content include:
- Baked goods
- Sugary drinks
These foods are all typically described as ‘carbs’ in popular usage. Because of this accepted abbreviation, when we say ‘carbs’ here, we are referring to these high carbohydrate containing foods. When we say ‘carbohydrates’ we are referring to the molecule found in said foods.
Carbohydrates are found in many more foods than the main suspects mentioned above. In fact, there are not many foods that will contain completely no carbohydrates. Vegetables and fruit are primarily made up of carbohydrates. Many pulses, beans, milk, seeds and nuts will also contain varying percentages of carbohydrates.
So, avoiding ‘carbs’ (as in pasta, potatoes etc.) doesn’t mean you aren’t ingesting carbohydrates at all.
We would describe a diet containing meat, fish, vegetables, fruit, nuts, seeds and some dairy products a ‘low/lower’ carbohydrate diet as opposed to a ‘zero’ carbohydrate diet – you will still get carbohydrates from many of those foods mentioned.
Pros of avoiding carbs
1. Reduced cravings
People who remove carbs for a period report less cravings for sugary foods. Many feel like their taste buds adjust.
If your body is used to a constant supply of sugary foods, as soon as one or two meals don’t include some sugar, the cravings kick in. The body wants that glucose.
A short period of low carb dieting may help some people deal better with cravings for junk food because of this, though there are often a few days of more intense cravings to get over first before that happens!
That said, very long-term low carb dieting could elicit the opposite response – the body craving carbs.
2. Insulin resistance leads to fat gain
If a meal contains high levels of carbohydrates, particularly simpler carbohydrates that are broken down quickly, blood sugars may rise quickly. This can cause insulin to be overproduced as it tries to keep blood sugar levels at a safe level.
Repeated overstimulation of insulin can lead the receptors on muscle and liver cells to become resistant to insulin.
This insulin resistance can lead to a greater percentage of consumed carbohydrates being stored as fat, rather than in the cells of skeletal muscle.
If a salesman knocked on your door five times a day to try and sell you something, you’d eventually stop going to answer the door.
Insulin is like that salesman knocking on the door of your muscle’s cells, trying to sell glycogen. Reducing carbs could help combat insulin resistance, since the salesman (insulin) will knock far less frequently.
3. Less carbs favours nutrients
Carbs are often used to bulk out meals in the typical Western diet. For example, a Spaghetti Bolognese. It has some beef mince, maybe some tomato in there, and then the other 70% of the meal is pasta.
No-one is going to argue that pasta, rice or bread have more nutritional value (from a vitamin, mineral and fibre stand point) than the same amount of veggies. Finding balance here is key.
Reducing carbs in the diet can help people shift the focus of their meals toward protein and veggies. It helps change the habit of adding carbs to every single meal while helping to bring carb quantities more clearly into our awareness.
As we’ll get onto, including carbs in the diet could well be a great thing. However, reducing carbs for a period may help put excessive carb intake into perspective. The goal for all effective diets is nutrient density, and calorie control – regardless of the amount of carbs eaten.
4. Low carb breakfast aids fat loss
If you have a breakfast very high in simple carbohydrates like bagels, toast or cereal, it can lead to big spikes in blood sugar not long after as those carbohydrates get digested fast.
These big peaks often lead to big troughs. By mid-morning, your blood sugar has crashed again and your body is craving sugar to try and elevate blood sugar levels again.
This is usually accompanied by a mid-morning crash in ‘real’ energy which just saps the will power right out of you.
Because of this, having a low-carb breakfast could help you keep calories in check. Additionally, studies show that protein has positive impacts on satiety, leaving you fuller until lunch.
For the best breakdown of the benefits of a high protein, low carbohydrate breakfast, check out our article on what to eat first thing in the morning HERE. We guarantee you’ll leave with everything you need to know about making the best breakfast choice possible for great energy and better fat loss.
For a sedentary lifestyle with limited exercise, reducing carbohydrates may be beneficial for improved fat loss and body composition. Keeping carbs low at breakfast could be the key to better energy and fat burning through the day. Of course, prioritising nutrient-dense foods such as protein, vegetables and fruit before including carbs is going to make a huge difference to your health and body transformation results.
With that said, reducing carbs will do nothing for you if it isn’t within an overall calorie deficit.
Just because you’re low carb, doesn’t mean you’re automatically fat burning if you’re eating too much. We’ll look more at the research on this later.
Cons of avoiding carbs
1. Reduced training intensity.
Glycogen is the most readily-available fuel source for anaerobic training, such as resistance training and interval training. We know from research and real-world experience that the best training modalities for fat loss and building lean muscle are resistance training and intervals. So, it makes sense to try and optimise these two types of training.
If you are training hard and burning off stored muscle glycogen regularly, refuelling those glycogen stores by including more carbs in the diet could drastically improve your ability to train hard. If you know us by now, you know we value training intelligently, but with intensity, to achieve the amazing transformations we produce at UP.
2. Muscle loss
Gluconeogenesis refers to a process in the body where proteins are turned into glycogen when glycogen stores are low. Limiting carbohydrates excessively could, therefore, result in muscle loss as the body tries to refill glycogen stores by breaking down muscle protein.
Additionally, insulin has anti-catabolic properties because it is considered an anabolic hormone. This means it helps preserve or build muscle. Since insulin is stimulated most strongly in response to eating carbohydrates, muscle building potential could be limited by a low carb diet. Less muscle will result in lower metabolism and worse body composition.
3. Sleep suffers
Very low carbohydrate diets can affect how well you sleep. Carbohydrates make tryptophan more available in the brain. Tryptophan is the building block for the neurotransmitter serotonin which is converted into melatonin. Melatonin is the hormone that gets you ready for sleep. Low carb diets could reduce tryptophan production, affecting the quality of your sleep.
When you add carbohydrates, you start to support melatonin production again. If you’ve ever gone out for lunch and had a big bowl of pasta, you’ll know that it’s not long before you fancy a mid-afternoon nap. While this response to eating carbs isn’t always desirable, such as before training, it can be a great option at dinner to help improve sleep.
In a study conducted by Afaghi et al., in the American Journal of Clinical Nutrition, the researchers found that a carbohydrate meal before bed significantly decreased the time it took for participants to fall asleep.
4. Metabolism may suffer
Restricting carbohydrates may affect the production of the hormone leptin. Leptin is a key survival hormone. It is produced by fat cells and its job is to communicate with the hypothalamus in the brain if we are likely to starve. If fat stores are low, leptin tells the brain to slow metabolism and increase hunger.
Leptin production can also be affected by long periods of low carbohydrate intake. Even when fat stores are not low, a long term low carbohydrate diet can trick the body into thinking it is starving. It, therefore, slows metabolism and increases hunger.
Eating carbs again can help stimulate leptin production. This will tell the brain to increase metabolism and reduce hunger. Many people find results stop quite quickly on a low carb diet but can be started again by including more carbs.
In one study, researchers found thyroid hormone was reduced on a low carb, calorie restricted diet. The calorie restricted diet that still included moderate carbs maintained healthy levels of thyroid hormone.
For anyone training hard, a low carbohydrate diet may not by optimal, especially not long term. It will affect training, muscle mass and recovery.
The better your training sessions, the better your results. We prove that day in and day out at UP.
However, your training sessions will mean nothing if you don’t recover properly from them, so improving your sleep by avoiding a very low carbohydrate diet could be essential. Additionally, carbohydrates could help keep your metabolism elevated, even during calorie restriction, leading to even faster fat loss.
There are pros to limiting carbs in the diet, as well as reasons to include them.
But ultimately, quantity of food still matters. If you want to lose fat, you must consider the number of calories you eat.
All the macronutrient manipulation in the world will do nothing if you’re eating too much food.
In fact, in many instances, the macronutrients seem to make no difference if calories are controlled. In one study, Naude et al. found no significant difference in weight loss between participants eating a low carbohydrate diet versus a diet with an equal number of calories.
On the other hand, Dansinger et al. conducted a systematic review of four popular diets.
Two of these focused on a moderate macronutrient split, one prioritised reducing carbs and one was calorie restricted. In all cases, fat loss was similar. Participants were free to eat as many calories as they liked on three of the diets but they lost comparable weight to the calorie restricted diet. So, does that mean calories don’t count?
Though calories were not tracked in all cases, it is likely that restricting certain macronutrients results in calorie restriction purely because it limits certain food groups. Ultimately, results are what matter.
Studies can only show us limited snapshots and are often unable to control all variables.
From our real-world experience, we know that if calories in are more than calories out, then regardless of carb intake, you will not burn fat.
You want the defining answer. The magic number of carbohydrates you’re supposed to consume in a day for maximum fat loss.
Unfortunately, if working with thousands of clients had taught us anything, it’s that the one ultimate rule about carbohydrates doesn’t exist.
This is partly since not one of our clients stays on the exact same nutritional plan from the start of their transformation to the end. We always need to adjust keep them progressing because the body will always adapt.
What we do know is that regularly raising blood sugar too high is not good for health or body composition. Controlling that doesn’t always require eating no carbs, however. Blood sugar can be well maintained by paying attention to the types of carbs being eaten. Some carbs raise blood sugar much more slowly than others. The speed at which a carb raises blood sugars is measured on the glycaemic index.
Which Carbs Should I Eat?
Choosing the right carbohydrates could have a big impact on your body composition. The classic measure of how fast a food will raise blood sugar is the glycaemic index (GI).
This index ranks different foods on how quickly they will raise blood sugar levels when compared to most simple form of carbohydrate – glucose.
Generally, the more complex the carbohydrate, the lower the GI. Foods below 55 on the index are considered ‘low GI’.
Anything above 70 is considered ‘high GI’. When including carbs in the diet, focusing on low GI foods will result in a more moderate blood sugar response which is beneficial to achieving optimal body composition.
Examples of low GI carbs
- Rolled Oats
- Natural Muesli
- Sweet Potatoes
- Pearled Barley
- Most Fruits
These foods are naturally high in fibre, making them much slower digesting and absorbing. They are also high in vitamins and minerals, making them great choices when including carbs in the diet.
When should I add carbs?
Making the right choice of carb is essential. But when should you eat them? Here’s our top three tips.
1. Less carbs to start
When you begin a body transformation, you’ll probably benefit from reducing carbs. If you’ve been consuming a typical Western diet, carbs have probably featured heavily during most meals and snacks. Less carbs will help you increase your protein and veg intake and the time away from a lot of sweet treats can help your body start using fat for energy more efficiently. When results slow, start to add some carbs with the next two tips.
2. Eat at night
Clients who have been on a low carb diet for a while may see their results slow or stop after a while. This is the body naturally adapting itself. At this point, adding some carbs may help accelerate fat loss again, giving you more available energy to train and recover. We generally add carbs to the evening meal first because they can improve sleep and, therefore, training, energy and recovery.
3. Earn them
Train. Train like you mean it. We’re serious about training. People train hard with us. If you’ve trained hard, you’ve burned off a lot of glycogen. You’ve earned those carbs and your body will be more likely to put them to good use – not just store them as body fat.
Therefore, post workout would be a good time to include carbohydrates – you need them.
In our experience, carbs are neither bad nor good. If you dogmatically avoid carbs, you may benefit from adding some. If you eat carbs at every meal, reducing them could stimulate progress.
We track progress religiously with our clients and adjust the carb amounts, timings and types based on the results they get.
Carbs can be both your friend and your enemy in the right situation. Finally, remember, regardless of your carb intake – calories still count.
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