15 Aug Carbohydrate: Separating Myth From Fact
No macronutrient has been debated as heavily, and with as much polarity as carbohydrate. With so many controversies, debates, cults associated with different usage of carbohydrates, it’s hard to know what’s right, and what you need to ignore.
You’ve got low carb, high carb, paleo, keto, carb cycling, nutrient timing, and a whole load of names designed to label a ‘type’ of diet.
At RNT, we subscribe to none of these. Instead, we focus on what type of diet fits your lifestyle in order to allow for maximum compliance and enjoyment. Some of these diets may be low carb, some may be high carb, and some may just be where most of you will need to sit: moderate carb.
In part three of this ‘setting up your diet series’, we’re going to dive into some of the myths surrounding carbohydrates, how they may actually benefit you in a fat loss diet, and how best to implement them effectively.
Myth 1: Eating Carbs Stops Fat Loss
The number one rule of fat loss is always going to be having a calorie deficit. Managing total calorie intake will always be key, and should be the first ‘pillar’ to hold in place when aiming to drop body fat.
If you want to gain weight, eat an excess of calories.
If you want to lose weight, eat a deficit of calories.
That being said, hormones can and do have an effect on how much the above two processes will occur. Which is why the following thought process has come to popularity in the mainstream:
Eat carbs > secret insulin > store body fat
While there’s a little more to it than this, it’s catchy, and is an idea for people to take, run away with, and create fear amongst us that we shouldn’t be eating carbs to drop body fat.
The thought is based on the following physiology. When insulin is raised, lipolysis (fat breakdown) is slowed down. It does this mainly via mechanisms:
– An increase in the enzyme Acetyl CoEnzyme A Carboxylase 2 (ACC2). This enzyme plays a role in fatty acid synthesis, and controls the transportation of free fatty acids into the mitochondria to be used.
– An inhibition of Hormone Sensitive Lipase (HSL) which has a role in mobilising fatty acids for energy.
You can see how this may have become over-simplified into ‘carbs > insulin > fat gain’. However, for healthy individuals, small increases in insulin after a carbohydrate rich meal are perfectly normal. The real key, which will come as no surprise, is ensuring calories remain in a negative energy balance. Over the course of 24 hours, your body will go through different phases of fat gain and fat loss, which all balance out by the time the next cycle begins.
This excellent graph by James Krieger1 portrays it well:
Myth 2: Eating Carbs Before Bed Will Make Me Fat
It’s incredible how this fallacy still exists.
Based on pure basic logic, it’s plausible to know why it first came about. You’re more sedentary in the evening and night time, your metabolic rate slows down, and so any carbohydrate consumed at this time will be stored as fat.
The science on the other hand tells a different story.
During the first half of sleep, metabolism drops by around 35%.
But here’s the cool thing…
Once you hit deep, or REM sleep, metabolic rate significantly increases.
What this means overall is that there’s no real difference between energy expenditure at night compared to at rest during the day.
More interestingly…and more applicable to us, is that exercises actually increases sleeping metabolic rate (and thus fat oxidation). And the leaner someone is, the greater the effect of this phenomenon!
This should debunk the myth as to why there’s no scientific reasoning of avoiding carbohydrates at night. In fact, many of our clients actually focus more of their carbs at night for the following reasons:
– Carbohydrate coax the body to release the relaxing hormone serotonin. This not only improves mood, but also quality of sleep. Multiple studies have also shown that poor sleeping patterns (<5 hours) can lead to reduced leptin levels, which creates more hunger, and makes adherence far more difficult in the day. This shift in carbohydrates to night time is often a big game changer for clients who struggle with sleep. It makes adherence easier, their recovery improves and ultimately their long-term training results take a turn for the better.
– A study performed by Isreali researchers2 found increased losses in total body weight, body fat and waist circumference when comparing night time carbohydrate feedings to carbohydrates eaten during the day.
Calories and macronutrients were matched in both groups, and the only difference was that the experimental group had 80% of their daily carbohydrate allowance at dinner, while the control group spread their carbs evenly.
In addition to body composition improvements, the experimental group also experienced improved satiety levels, insulin sensitivity and a reduction in inflammatory markers.
– It allows you to be more social. This is typically the time many people eat out and with others, so it always makes it easier if you have a little more ‘allowance’ for dinner time to enjoy a satiating meal with family and friends.
So We Should Now Eat All The Carbs?
Not so fast… we may have debunked the myths surrounding carbohydrates, but this doesn’t mean you can start pounding the carbs ad lib at each meal. Our purpose was to show that the incessant scare mongering around carbs is unwarranted.
When setting up a fat loss diet, there are some very good reasons for 80-90% of you to start with carbs in there.
Firstly, calorie restricted diets that include carbs typically leave most dieters in a better mood. Sleep will be improved (timing dependent, as per earlier) due to the carbohydrate – serotonin relationship. Both of these are typically negative affected by low carb diets.
Secondly, carbs will help maximise muscle gain and retention. During times of stress (i.e. dieting or training), when glucose becomes a primary source of fuel (i.e. anaerobic exercise), carbs will be much more muscle sparing than fat.
What can typically happen in low energy states such as when dieting, your body may look to produce energy by converting amino acids (from protein) to glucose (gluconeogenesis). Carbs can prevent this, since they are more easily broken down and converted into glucose. This then allows dietary protein to be spared from use, and instead stored/utilised for muscle growth and repair.
Thirdly, carbohydrates can lessen the blow to metabolism that a low carb diet may cause. Two key fat loss hormones involved here are T3 (thyroid hormone) and leptin.
T3 is largely dictated by calorie intake. Typically what happens when someone goes low carb is they go very low calorie too, and fail to replace lost calories from carbs with protein or fat. Over time this can keep you in an extremely hard calorie deficit which can slow your T3 production down in an attempt to regulate body fat levels.
Leptin is stimulated by carbohydrate intake and energy availability. By restricting carbs for too long, leptin down-regulates. This can create a recipe for disaster, as your metabolism can slow down while at the same time sending your hunger levels sky high.
Should You Avoid Low Carb Dieting?
It’s important that the context of this article is understood. This is how we would start a fat loss diet, not necessarily how we would approach it later.
The overall aim is to diet on as many carbs and calories as possible while still dropping body fat. But there will be necessary periods of lower carbs for most, and phase that will need to be embraced.
While we talked about low energy states, potential muscle loss and impaired performance when low carb dieting, it’s also always surprising just how resilient and strong the body is. Many of the potential downsides of low carb dieting phases can be reduced through the right mindset and approach to your training. This isn’t necessarily backed by science, but more through years of experience working with clients.
Merits of Low Carbs
One population that may benefit from a low carbohydrate diet are females suffering from PCOS (Poly-Cystic Ovarian Syndrome). PCOS seems to go hand in hand with insulin resistance, and there are strong links3 highlighting the positive effects (in both weight and symptoms) of a low carb diet for women with PCOS.
The other times they work well from the start are for those who want very fast results on a short time frame (<6 weeks), or for those who struggle with carb cravings. For these people, going ‘all out’ can help eliminate this, and ultimately bring about increased adherence to the diet.
We also come across some people who just ‘prefer’ eating more fat and less carbs, so as long as they stay within their maximum calorie allowance, and reach their minimum protein requirement, this approach also works well.
Remember, the number one factor in fat loss results? Compliance to a calorie deficit!
How Many Carbs Should You Eat?
Before working out how many carbs you’re going to start with, you need to know your calorie intake (which we’ll discuss in the next instalment), as well as your protein and fat requirements.
Once you’ve set these, carbohydrates will simply make up the remainder of the calories left over.
For example, let’s say our example male client required 2000 calories to lose body fat.
His protein target is 200g a day, or 800 calories. His fat intake should be 70g a day, or 630 calories.
2000 (total calories) minus 800 (protein calories) minus 630 (fat calories) leaves us 570 calories left over for carbs.
If we divide 570 by four, we’re left with approximately 140g a day for carbs.
This makes the overall targets:
What Type of Carbs?
We like to keep this really simple, and let two factors guide your carb choices: hunger and taste preference.
This usually eliminates a lot of the typical ‘junk’ foods like sweets out of your diet, because trying to comply to a small amount of sweets while also feeling satiated is next to impossible when you’re dieting hard.
By default, you end up resorting to what are typically considered ‘traditional’ dieting carbs, such as sweet potato, oats, rice, etc.
If you’re in a gaining phase with plenty of calories, this section would likely be longer and more interesting. But for fat loss you can’t go wrong with keeping your food choices simple.
Focus on satiation, and then let taste guide your food choice. If hunger is under control, whether you choose white potato or sweet potato, white rice or brown rice, really doesn’t matter.
When Should You Eat Your Carbs?
In the grand scheme of things, how you spread your carbs out in the day doesn’t have that much of an impact on your results.
Our clients are everyday people with busy lives, so our main focus is always on 24 hour compliance before getting into the minutia.
If you’re nailing the big picture, and wanted to look for an extra 1-2% edge, then there are three scenarios you may want to consider.
Assuming you train at night, there may be a small benefit to omitting carbs at breakfast.
The first benefit of this is you’ll be able to increase training performance if you save some more carbs for later in the day. The second is you may potentially experience less hunger and cravings, given we’re typically busier in the mornings. The last is you may be able to lengthen the period of lipolysis, which is the time spent in the ‘blue zone’, if you remember the graph from earlier.
Around Your Workout:
There’s definitely something to be said for keeping carbs around your workout for as long as possible. At the beginning, you may want to spread it in the day, but as you make subtractions, try keep it away from the workout while you can.
There are three windows; before, during and after.
Placing a percentage of your total carbs around 60 to 90 minutes before a session is going to give you more energy and consequently improve performance.
When it comes to during the workout, it really depends on your carb allowance. If you have sufficient carbs, then utilising an easily digested carbohydrate shake can be an option. But if it comes between a choice of using food or a shake, opt for food. It’ll keep you far more satiated in lower calorie periods.
If you are going to use an intra workout shake, then combining Highly Branched Cyclic Dextrin as your carb source with EAAs as your protein source is the preferred option. You can start sipping on these 15 minutes prior to training, and continue drinking throughout. Both are easily digestible, don’t cause nausea and release into the bloodstream quickly.
The third window is after your workout, when your muscle cells are most sensitive to glucose uptake through a process known as ‘glut-4 translocation’. In layman’s, this means the muscle cell specific glucose transporter protein rise to the surface of the cell and help pull glucose from the bloodstream and into the cell.
You can see how this works in the image below:
By keeping the time around your workout nutrient heavy, you can help facilitate muscle retention (and maybe some growth) during a dieting phase. Remember, your one hour in the gym should be treated as the time to do everything possible to ‘build’ your physique. Leave the other 23 hours in the day to focus on fat loss through your cardio and diet.
We touched on this earlier, but keeping some carbs at night can help with sleep quality, socialising and overall compliance.
Many of our clients will prefer to keep carbs here over anywhere else, simply because it helps them unwind after a long day and adhere better to the plan.
Big Picture Thinking
Despite us talking about the myths, merits and uses of carbohydrate in this article, there’s been an underlying theme of focusing on what really matters.
For fat loss, it’s always going to be compliance to a negative energy balance. Without this, no amount of nutrient timing, low carb dieting or carb cycling will make a difference.
Focus on the calorie deficit, then focus your carbohydrate intake on making it as easy as possible to stick to it on a daily basis.
1 James Krieger’s Weightology.net – https://weightology.net/insulin-an-undeserved-bad-reputation
2 Sofer, Sigal, et al. “Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner.” Obesity 19.10 (2011): 2006-2014.
3 John C Mavropoulos, William S Yancy et al (2005) The Effects of Low-Carbohydrate, Ketogenic diet on the Polycystic ovary syndrome: Journal Nutrition & Metabolism
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