“I tried every diet and nothing worked, then I cut carbs and the weight just fell off.”
How often have you heard this? Even if you don’t work in fitness industry, you’ve probably had this exact same conversation at a dinner party, family gathering, or when just out with friends.
You will lose weight if you cut down on carbs. Seems legit, right? The anecdotal evidence is there, and it seems that science supports the notion that low carbohydrate diets are great for weight loss too.
I like to make research, and a quick Google search for studies supporting low-carb diets as a method for losing weight brings up an absolute tonne – a veritable smorgasbord of evidence backing low-carb plans – it’s every Atkins follower’s wet dream.
Let’s take a look …..
“Low-carb diet appears to be an effective method for short-term weight loss in overweight adolescents and does not harm the lipid profile” (source)
“Severely obese subjects with a high prevalence of diabetes or the metabolic syndrome lost more weight during six months on a carbohydrate-restricted diet than on a calorie- and fat-restricted diet, with a relative improvement in insulin sensitivity and triglyceride levels, even after adjustment for the amount of weight lost.” (source)
“Compared with the low fat group, who followed a diet conforming to currently recommended distributions of macronutrient calories, the very low carbohydrate group lost significantly more weight.” (source)
“Low-carbohydrate diets may be effective alternatives to low-fat diets.” (source)
These are just some of the quotes taken from studies that showed low-carb diets to be effective in losing weight and improving body composition. That’s it then. Article finished.
We should all ditch our grains, fruit and veggies and live off nothing but meat and fish.
Before you leave, let’s look a little deeper before deciding to forego carbs completely.
On the face of it, low-carb diets seem like the best thing since sliced bread. Well, the best thing since boiled eggs and grass-fed beef in this instance. So why then, are they not only unnecessary, but also potentially harmful?
Mass Media Hype
Back in the 80s and 90s, we were all about high-carb, low-fat diets. Everything had to be whole-grain this, whole-wheat that. We were told to limit our fat intake, and heaven forbid should we ever consume butter, red meat, or anything with saturated fat in it, may the lord strike us down with a cholesterol-induced fist of death.
Then in 2002, along came a gentleman by the name of Gary Taubes.
Taubes had his article “What if it’s All Been a Big Fat Lie” published in the New York Times, and suddenly, the world went low-carb crazy. (source)
We could eat anything we wanted and get slimmer, provided we kept our carb intake ultra low. That meant breakfasts of eggs and bacon, a garden salad dripping with olive oil for lunch, steak cooked in butter for dinner, and snacks of beef jerky, pork scratchings and nuts. Sales of Dr. Robert Atkins’ booked soared and despite it being released originally in 1972, sales hit their peak around 2003, when it’s estimated that almost 10 percent of North Americans were following Atkins’ plan.
Why Low-Carb Sells
Low-carb sells for one main reason – it’s extreme.
The layperson loves extremism. They associate extremism with success. If a diet’s weird or difficult, it’s got to give great results, right? Just look at the popularity of Atkins, the cabbage soup diet, the baby food diet, raw eating, juice detoxes – the list goes on.
Eliminate a whole food group from your diet? That sounds extreme, it must work!
Read also: Why You Should Not Go For Extreme Diet
The second reason why low-carb diets sell is because of the initial rapid weight loss you experience. At the start of a low-carb diet, you may lose a good 7 or 8 pounds in the first couple of weeks. While some of this loss might be fat loss, the majority of it will be water and glycogen. Under normal dietary circumstances (ie. A moderate or higher carb diet) your body has ample supplies of carbohydrate in the muscle cells and liver. This stored carbohydrate (known as glycogen) not only adds weight itself, but each gram of stored carbohydrate carries with it around 3 to 4 grams of water.
The average person can store up to 350g of glycogen in the muscles, 100g in the liver and a little more in circulating blood too.
That adds up to 450 grams, give or take. Multiply that by three to find roughly how much water you’re also holding along with this glycogen, and you hit a total of 1,400 grams. That’s a loss of 1.4kg, or just over 3 pounds by eliminating stored glycogen from your system.
Now you can see why this rapid weight loss occurs.
Why Low-Carb Advocates SAY Their Diets Work
Proponents of the low-carb approach like to preach about the metabolic benefits their diet supposedly offers.
This is in true to a degree.
In his NY Times article, along with the books and articles he’s published since, Taubes claims that we can eat virtually whatever we like and not get fat, provided we avoid carbs. (Another reason why low-carb seems appealing – who wouldn’t want to eat unlimited amounts of bacon, cream, butter and steak?) According to Taubes, the reason why we should give carbs a wide berth is because of the effect they have on our levels of the hormone insulin.
Rather than address the whole topic of insulin here, I’ll direct you to the first article of an excellent seven part article by James Krieger of Weightology.com – Insulin – an undeserved bad reputation.
As a brief coverall, insulin is the hormone released when you eat a meal, as it helps shuttle nutrients around the body. Any insulin release will acutely inhibit fat burning, leading to the theory that we need to keep insulin levels as low as possible to sustain fat burning.
Carbohydrates have the biggest insulinogenic effect of all the macronutrients, therefore, low-carbers deduced that by lowering carb intake, we lower insulin levels, and therefore create a metabolically advantageous environment, burn more fat and lose more weight.
The truth, however, is a different story.
There are several highly regarded myths surrounding insulin and fat storage. (I’ll direct you again to Krieger’s articles for more on these) but in short, they are –
Eating carbs leads to chronically high insulin levels
FALSE –In otherwise healthy individuals, insulin only spikes after a meal – it does not stay elevated for hours on end.
You only store fat when you eat carbs and spike insulin levels
FALSE – You can still store fat when insulin levels are low.
Insulin increases hunger
FALSE – Insulin actually suppresses appetite.
Carbohydrate is the only macronutrient that can raise insulin
FALSE – Protein spikes insulin too. In fact, whey protein post-workout is highly insulinogenic.
Lowering insulin will automatically lead to fat loss and weight loss
FALSE – Calorie balance is what drives weight and fat loss, not insulin.
So, with the insulin theory well and truly busted, what have the low-carbers got to go on now?
Why Low Carb REALLY Works
I’m certainly not anti low-carb. In fact, many follow what the vast majority of people would deem a “low-carb diet.” While I prefer to refer to these as individualised carb diets, or targeted carb diets, as I believe carbohydrate levels should be set according to the individual, there are several reasons why lowering your carbs can certainly bring about results.
1. By lowering carbs, you reduce your calories
Think of the typical Western diet.
Most folks will usually start their day with toast, cereal or some sort of cereal bar, with maybe a sugary coffee or a fruit juice on the side. Lunch is something in a sandwich, accompanied by a bag of crisps, perhaps with a piece or two of fruit and a chocolate bar or another carb-filled drink. Evening meals invariably revolve around pasta, rice or potatoes. As for snacks, we’re talking more fruit, low-fat snack bars, crackers and rice cakes for the health conscious, or sweets, biscuits and donuts for the not-so-healthy. Total all this up and you get….. a crap-tonne of carbs!
Even someone eating small to moderate portions can easily put away 200 grams plus of carbs in a day. That’s 800 calories. Reduce your daily calorie intake by 800, and there’s no doubt whatsoever that you’ll drop pounds.
2. Low-carb diets tend to be higher in protein
What do you think of when I say “low-carb breakfast?”
I’m guessing it’s that Atkins classic of bacon and eggs? Not only is this low in carbs, but it’s high in protein too.
How about lunch? Probably some sort of salad with chicken, tuna or turkey, right? A low-carb dinner is a steak with veggies, and snacks are nuts, olives and cheese.
Compare that to the typical Western diet discussed before, and not only is there a big drop in carbs, but also a high rise in protein. And that’s the second reason why low-carb diets can be highly beneficial.
By dropping carbs, people don’t just lower their carb intake, they look for other foods to replace carb-dense items with. This inevitably leads to a higher protein intake, and protein is well-known to be a powerful appetite suppressant. Eat more protein and you’ll feel much fuller. Don’t believe me? Here’s an experiment to try –
– Eat a couple of plain rice cakes and note how soon afterwards you feel hungry. It’ll probably only take around an hour for you to feel peckish again. Now eat just one rice cake with a piece of sliced turkey or ham. The calorie content will be virtually the same as the two rice cakes earlier, but it’ll probably take double the amount of time for you to get hungry again.
Protein also has a slightly higher thermic effect of food (TEF) than carbs or fats do. Basically, it takes more energy and more calories for your body to break down and digest protein, leading to a lower net calorie intake from protein-dense meals. This is a key reason why there may be some small metabolic advantage to low-carb diets. It’s not the lack of carbs that provides this effect, but the increase in protein.
3. Low-Carb Diets Reduce Hunger
This links in with the above high protein intake. Many studies that compare low carb to high carb diets don’t dictate any calorie intake to participants. Because of the satiating effect of higher protein foods, this means low-carbers eat fewer calories overall, thus leading to weight loss.
As you can see, while low-carb diets may have their benefits, it’s not actually the reduction of carbohydrates that leads directly to weight loss. I guess were we to leave the article here, you’d probably come away with a neutral to positive view of dropping carbohydrates. You might not be quite embracing the zealot-like approach of our friends Messrs Taubes and Atkins, but you’d probably be thinking “hey, that low-carb stuff seems to work, I’ll give up bread and pasta and see what happens.”
If that’s what you decide to go with, so be it. If it suits your lifestyle and gets you results, it’s probably a pretty good call. However, before making your mind up, finish reading the article to see why low-carb diets could do you more harm than good.
Why Going Low-Carb is a Bad Idea
Before getting into the physiological reasons against low-carb diets, let’s see why they suck from a psychological standpoint.
A Matter of Taste
First up, who doesn’t like carbs?
There’s something so comforting about a warm piece of toast on a cold winter’s morning, a steaming bowl of pasta after a tough day, and the lure of a sweet potato smothered in honey and peanut butter can keep you going through the most gruelling of training sessions.
It sounds kind of fruity (pun intended) but there’s a lot to be said for enjoying a diet.
The main reason people fall off the dieting wagon is very rarely due to a lack of results. Moreso it’s bordedom and irritation at having to follow such a strict meal plan. If you enjoy eating carbs, why wouldn’t you find a way to lose fat and get lean while eating them?
One of the first questions I ask new clients when designing their plan is “Do you prefer carb-dense foods like pasta, potatoes and bread, or fat-heavy foods like cheese, bacon and cream?” If the person responds with the former, I make sure they get a higher proportion of their calories from carbs, so they enjoy what they’re eating and are far more likely to stick with their plan long term.
Most cereal dieters (yes, pun number 2!) have experimented with low-carb diets at some point. The one comment you’ll hear time and time again – “It worked, but I felt terrible.”
This is due to what’s become known as the “low-carb flu.”
It refers to the period of time it takes your body to adapt to using fat as its main energy source instead of carbs. This is no myth that low-carb avoiders make up or embellish either – even the Atkins site recognises that the huge majority of people will experience feelings of tiredness, lethargy, fatigue and irritability when starting a low-carb plan.
Their solution – work through it, your body will adapt.
It usually takes 3 to 4 days (though it can be longer) for your body to switch over fully to running on ketones (the compound produced when you go low-carb.) Many people do find they can get through this however, as this flu/brain fog coincides with the initial rapid weight loss as discussed earlier, so while they might feel like crap, they love the results.
My issue with this however, is it once again links dieting with suffering. I firmly believe that dieting should be made as little like a chore as possible. If you feel bad, how long will you really persevere? And considering the supposed benefits of carb restriction are so grossly overstated, as discussed in previous sections, you have to question whether this drop in mood, libido and energy is even worth whatever miniscule benefit you might be hoping for.
I’ll admit it, eating low-carb meals at home is really easy. Eggs, bacon, veggies, Greek yoghurt for breakfast, and plenty of meat, fish, more vegetables, nuts, seeds and other pretty tasty low-carb treats every day. But what about when you’re out and about?
While it’s certainly doable to stick to low-carb fare all the time, it can be an annoyance and cause you to have to do far more planning than you would otherwise. Eating at work becomes more of a chore, as does choosing foods at restaurants. Friends start to question your food choices – why you’re not eating bread, why you’re not drinking — and can potentially feel irritated that you’re gradually becoming a social outcast because of your dietary restrictions.
Carbs Are Fuel
Carbs are your body’s main source of energy. And a damn good energy source they are.
The energy pathway required for explosive muscular contractions is the ATP-PC system, which relies on ATP (adenosine tri-phosphate) breaking down to form ADP (adenosine di-phosphate.) This can only be sustained for a short time however (usually around 8-10 seconds) so after this, a second energy system has to come into play. This second energy system is the glycolytic system, which uses stored carbohydrate to create energy. After this tapers off, your body switches to aerobic metabolism, which uses a mix of carbs and fats for fuel.
The trouble with low-carb diets here, is that the glycolytic system (and to a degree, the ATP-PC system too) relies on a ready supply of glucose and glycogen – ie. Carbs. Low levels of carbs = low energy levels for higher intensity activities = crappy performance.
Sure, for marathon runners, iron man triathletes and the steady Sunday morning dog walkers, fats might be a fine fuel source for sustained, low-intensity exercise, but for anyone concerned with strength, power and performance, carbs play a critical role.
Low-Carb and Your Thyroid
T3 is a very important thyroid hormone, which helps to regulate your metabolism, growth and development, body temperature, and heart rate.
In low-carb diets, it appears that production of T3 drops, along with your levels of other thyroid and metabolism hormones.
When you hear that a woman is having trouble adhering to a ketogenic diet, it could be due to lower T3 or increased inflammatory acidity. She might also say that she has had weeks of keto flu and has given up. You might also hear her complaining that she is so upset and keto-crazy about the whole experience, she has not only lost contact with her family and pet dog but has also indulged in chocolate chip cookies as well as wine for three days (before she gave up completely on the diet).
Carbs are Muscle Sparing
This relates back to athletes’ needs for carbs. Carbs are much more muscle sparing than fats in times when your energy stores are lower. Your body can attempt to convert amino acids into energy, which leads to muscle breakdown. By providing a ready source of energy however, carbohydrates prevent this.
Protein itself is muscle sparing too, which is why you may actually increase your protein intake when decreasing calories for a cut or fat loss diet, but keeping carbs in will go a long way to preserving muscle mass.
Bottom line: Want to retain muscle? Eat carbs.
Low-Carb Doesn’t Take Into Account Protein and Fat Calories
Most, though admittedly not all, low-carb diets, don’t give recommendations on protein and fat intake. The theory being that by reducing carbs, the average person can eat a little more fat and protein, yet still be in a calorie deficit and lose fat while feeling full.
Here’s the problem though – while a low-carb diet consisting of lean meats, fish, eggs whites, dark green vegetables and healthy fats like olives, oily fish and a little cheese may allow you to eat large amounts of food without much of a dent in your total calorie intake, this isn’t how many people do low-carb diets.
As an example, take a look at the calorie contents of two low-carb dieters. Assume neither dieter has been given any recommendations other than “cut out all high-carb foods” –
Dieter 1 –
Breakfast – Omelet made with 2 eggs whites, 2 whole eggs, onions, mushrooms and tomatoes with a sprinkling of cheese.
Lunch – Mixed green salad with a grilled chicken breast, and one handful each of pine nuts and olives.
Dinner – Medium-sized lean sirloin steak with broccoli, carrots and spinach.
Snacks – 1 packet of deli-style beef, small low-fat low-sugar Greek yogurt with strawberries.
Daily macronutrient count – 140g protein, 60g carbs, 70g fat, 1430 calories.
Dieter 2 –
Breakfast – 4 whole eggs, 2 rashers of bacon cooked in 1 tbsp butter.
Lunch – 2 chicken thighs with a dark green salad and a handful of cheese.
Dinner – Pork belly, served with green beans, kale and spring greens cooked in butter.
Snacks – handful of macadamia nuts, small block of cheese.
Daily macronutrient count – 140g protein, 35g carbs, 140g fat, 1960 calories.
Both the above diets contain the same amount of protein, and the second is slightly lower in carbs, yet contains over 500 more calories. Neither is particularly extreme in terms of either a lack of, or an abundance of foods, yet simply by “going low-carb” you can end up with wildly varying caloric intakes.
Even the most ardent of low-carb advocates would struggle to argue that a difference of 500 calories per day wouldn’t have an effect on long-term dieting and physique progress.
The Wrap Up:
So how many carbs should I eat?
As, the existential question – what’s the precise number of carbohydrates you should eat per day. And if low-carb is a poor choice, then does that mean a diet should be high in carbs?
As always, the answer is, annoyingly, it depends.
Carb intake is a highly individual thing – the amount of carbs you eat per day depends on your goals, current weight and body composition, your activity levels, and to a certain degree your genetics and dieting history.
Now, if you’re slightly confused, I am absolutely not saying that low-carb diets are bad, nor am I suggesting you don’t drop a single gram of carbohydrate from your diet when attempting to lose fat. I’m merely saying that simply going low-carb is not the most effective, nor practical way to lose weight in the vast majority of cases.
Carbs have been made a scapegoat for rising obesity levels, when in actuality, a vast array of factors have all played a role in our getting fatter. We do now eat more carbohydrates from grains, caloric sweeteners, fruits and vegetables than we did in 1970, but we also eat much more fat and oils, cheese, red meat, poultry and shellfish too. In essence, we seem to eat more of almost every food group now, leading to an average increase of around 500 calories per person per day from 40 years ago.
It’s this calorie increase, not an unrivalled increase in carbohydrate consumption that needs to be addressed. Unfortunately however, many still have this idea in their head that carbs need to be slashed to lose weight, that they’re the sole cause of weight gain and an obesity epidemic, and that when cutting carbs you can eat all other foods ad infinitum and still make progress.
But that’s not going to happen. By automatically adopting the low-carb approach, you’re setting yourself up for failure, misery and potentially screwing with your health and performance.
In my next article I’ll address exactly how to tailor your carb intake to suit your goals, but for now, you can rest safe in the knowledge that that sandwich you had for your lunch isn’t going to suddenly materialise in the form of adipose tissue right around your stomach.