READ TIME: 1 x long black w/ cream cheese bagel on the side (6 min)
KEY POINTS:
In the past 5 years there’s been a resurgence in low-carb and ketogenic diets as the obesity-blame spotlight has fallen on carbohydrates.
This dogmatic fear of carbs is based upon limited evidence and a whole lot of anecdotal reports.
The evidence as a whole shows that carbohydrates aren’t inherently fattening and are not the sole cause of obesity.
We need to stop pointing the finger at individual nutrients or foods as the problems/solutions and start looking at individualising diets based on whats going to lead to the best adherence.
I'm not anti-keto. Or anti-LCHF.
Nor am I pro-high carb.
I am however anti-idiot.
And anti-invent bullshit problems to confuse people and then provide them with an expensive solution. (So pretty much the majority of nutrition information available.)
Recently a client linked me to a Facebook video with the title of "Fat doesn't make you fat, carbs do". Ten minutes later and I looked like I'd stepped in the ring with Conor McGregor due to the vigorous facepalming that had taken place.
Most of us have probably been exposed to something similar, and it's not surprising. Keto or low carb diets are #trending at the moment. Every second self-taught celebrity chef is releasing a "fats awesome, carbs are the devil"-esque type book, and plenty of #fitspo-grammers are also spouting the benefits of a high fat, low carb approach.
In my opinion this sudden popularity is down to a few factors:
1) It appeals to the way us lazy humans like to think.
In black and white terms.
Don't give us grey.
Don't make us think about context or specifics.
Just provide us with a simple blanket statement that we can apply to all situations.
Never eat [insert food]. Only eat [insert foods]. Or just eat at [insert times].
These types of simple dichomtous rules require a lot less time and energy than thinking logically and applying context. Hence why logical, context-dependent solutions aren't likely to be bestsellers any time soon.
2) It makes for an entertaining and marketable story.
"Once upon a time, the evil authorities forged a despicable document called the dietary guidelines. These were crafted to destroy our health, give us chronic diseases and lead us to obesity.
Among these guidelines was the recommendation to eat less fat and fatty foods. And so started the dark years, where dietary fat was demonised, high carb diets were favoured, and we continued to grow fatter.
But never fear, the brave knights of truth and justice have come to set things straight. To proclaim that fat is not only not evil but amazing and that in fact, it's carbs and sugar that are to blame for our current obesity epidemic."
The problem with this story though, for it to be true, the population would have had to follow the guidelines in the first place.
They didn't. Fat intake did not decrease.
The contribution of fat to our diets increased during this time.
Along with many other factors that lead us to consume more calories then we expend on a daily basis.
3) It makes sense at face value.
The idea that a reduced carb diet decreases insulin secretion causing increased fat burning and therefore fat loss makes sense at face value. Add a few sciency sounding words like lipolysis and oxidation and BOOM! Now it has to be true.
4. We Love Anecdotal evidence (and don't understand scientific evidence).
"Well, I lost "X" kilos following a low carb diet after trying everything else and failing."
Eerrghhh, where do I begin?
Anecdotal evidence is the lowest form of evidence.
Why?
Many reasons. Including the fact that in everyday life it's near impossible to isolate variables which is what's required to figure out what caused what.
Whenever we think 'X happened before Y' therefore 'X must have caused Y' we're making a logical fallacy.
So when someone says "Well I started a vegan diet and lost 10 kilos in 6 months" as an argument for vegan diets, that doesn't tell us anything except they lost 10 kilos because something changed. How do we know that it was the lack of animal products that caused those results? Perhaps it was a reduction in energy intake and an increase in the quality of their diet?
I could continue but to save time here's a good article that covers many of the flaws of anecdotal evidence.
These four factors drive a pretty convincing story. One that I too bought into, before my time studying at university.
One of the biggest lessons I learnt during my time studying but also through interacting with other evidence-based practitioners was the importance of critical thinking.
Of asking the right questions.
One of the best ways to do that is by asking yourself " if [insert statement/hypothesis] were to be true, what would I expect/not expect to see?"
For example.
If carbs really are the problem, what would we expect to see or not see?
Well, you might expect certain cultures with higher carbohydrate intakes to have higher rates of obesity than others, right?
In 1990, Dr Staffan Lindeberg spent 7 weeks living and studying a tribe on Kitava Island, Papua New Guinea. During his time Dr Lindeberg found that despite having a diet rich in carbohydrate, (70%) coming mostly from taro, yams, sweet potatoes and fruit, that they were remarkably healthy with almost non-existent levels of obesity, diabetes, heart attacks or strokes well into old age.
Japan has one of the lowest rates of obesity when it comes to first world countries, with an impressively low 4.3%, despite having a relatively high carbohydrate diet. Unfortunately just like other first world countries overweight/obesity rates are steadily increasing. What isn't growing, however, is the percentage of their diets coming from carbs. In fact, in the last 20-30 years, we've seen carbs decrease, and fat intake increase as their old dietary patterns shift towards a more Westernised diet.
Korea has also seen a similar shift in the last 15 years with obesity increasing. During that time, population data indicates that the % of energy in the diet from carbohydrate has slightly dropped (66% to 60%) while energy from fat has increased (16%-20%).
Even in Westernised cultures, the observational evidence overall suggests that carbohydrate intake isn't inherently fattening.
What else would we expect to see?
Perhaps that a lower carb diet would result in less fat gain than a higher carb diet when subjects are overfed aka a calorie surplus?
Nope.
While there's not a lot of studies comparing overfeeding of different macronutrient ratios, collectively they show no difference in fat gain whether the surplus comes from fat or carbohydrates when energy intake and protein is matched.
What about when dieting?
If carbs are more fattening then wouldn't we expect to see individuals lose more body fat over time with lower carb diets?
Studies have shown greater short-term weight loss with low-carb diets in obese patients. However, these studies relied on self-reported dietary intake data which can be notoriously inaccurate. Which makes it hard to accurately know the adherence to the diets and whether it was the lower carb intake or a lower calorie intake that caused the results.
This is highly plausible as one of the strengths of low carb or keto diets are that they do tend to result in inadvertent decreases in overall calories.
However, when we look at controlled settings, where overall energy intake, protein and energy expenditure are accounted for, then we get a clearer picture of whether there is a fat loss advantage to a lower carb approach.
Hall and colleagues did a great job in gathering and analysing the controlled studies looking at this. They conducted a systematic review and meta-analysis (compiled all the individual studies to look at the subject as a whole) looking at whether there was an advantage to low carbohydrate diets.
They only included controlled feeding studies where food was provided to the subjects (increases adherence) and compared diets with carbs varying from 1% to 83% and fat ranging from 4% to 84%.
Their results?
Low-fat diets resulted in greater fat loss than low-carb diets. The opposite of what we'd expect based on the hypothesis. The difference, however, was so small it was practically insignificant.
Let me be clear.
I'm not saying that fat is driving obesity rates, or that carbohydrates don't have a part to play. I'm just illustrating that the evidence as a whole doesn't fit the statement/hypothesis that carbs are inherently fattening or driving obesity.
No one factor is.
Obesity is a complex problem that doesn't have a simple fix. In fact, it's so f**cking complex it blows my mind and there is a lot we don't know.
What we do know is that an imbalance between energy intake and expenditure is what leads to fat gain.
I can also confidently say that pointing fingers at individual foods or nutrients as being the problem isn't helping and anyone who you find doing so is likely benefitting from it financially.
The secret sauce isn't in the methods. You're not going to find long-term success by removing or adding one food from your diet.
It's in ADHERENCE.
In finding a diet you can stick while living in this environment that pushes you in the opposite direction.
It's in creating your own method that allows you to tick the general nutrition principles consistently over time.
That's essentially my job.
Helping individuals find their own personal diet that allows them to consistently tick the HIGH ROI factors with the least amount of effort.
Let me know how I can help you.
Seriously. Whether it's a personal chat, an article on a topic you're not sure on, a video etc.
Let me know below or hit me up.
I'll respond within 48 hours guaranteed.