Emma Storey-Gordon

Note from the editor:

I’m sure you’ve all heard how amazing low carbohydrate diets are- but whenever someone starts telling you why you should try one, they always start with how terrible carbohydrates are. They spike insulin, promote fat storage, and that the overconsumption of carbs is the cause of the obesity epidemic.

If you’re a frequent reader of SBS articles, or a keen podcast listener, you’ll know this to be false. We’ve written before about how there’s no unique benefit to low-carb dieting from a physiological or thermodynamic standpoint.

In this guest article, our good friend Emma Storey-Gordon is going to give you the low-down on the real-life benefits, drawbacks, and mistakes that you want to avoid when it comes to low-carb diets.

The Top 5 Benefits of Low Carb Diets

1) Hunger and protein

Low carb usually means higher protein, which has been shown to increase satiety, reduce hunger and help maintain lean body mass. This all likely contributes to the perceived ease of a diet, long term adherence and how good you look!

2) Diet control

It is very easy to over eat carbs, especially if your food choices are more refined and/or heavily processed. Limiting them reduces the chances of over eating. Dieting is far more psychological than we give credit for – simply telling someone to “be in a calorie deficit” or “eat less and move more” is fairly useless advice unless they’re very highly educated. Going low carb may have a psychological edge in that, in most cases, you can create a deficit just by reducing your carbs as opposed to counting calories.

NB: calories still count even if you don’t count them! There are no two ways about it – you will have to be consuming fewer calories than you expend to lose weight.

3) Carbohydrates often make up a large proportion of our excess calorie intake

Carbohydrate reduction is usually a good place to start when aiming to reduce calories as our typical western diet is high in carbohydrates. Technically you don’t need carbohydrates from your diet to survive – they’re not an essential nutrient, meaning that your body can produce enough glucose to survive from the other macronutrients. Protein and fat, on the other hand, do need to be consumed from our diets as our bodies are unable to synthesise certain amino acids and fatty acids.

Although it’s likely we find ourselves over weight because of general over-indulgence rather than over-eating a specific macronutrient, carbohydrates are generally found in excess so are a good starting point when reducing calories.

Further to this, high carbohydrate foods often tend to be high-fat foods too (a.k.a. hyper-palatable foods), which are not only very calorie-dense but also not especially filling.

Note from the editor – we recently produced a podcast episode about hyper-palatable foods. Have a listen!

4) Simple

Reducing your carbohydrate intake is fairly simple and easy to implement – it doesn’t necessarily require counting calories, and seems to be an appealing way to diet. Little knowledge is needed to reduce your carbohydrate intake – it can be as simple as halving your starchy carb portion and filling the plate with salad or vegetables. For some people simply avoiding bread can create a substantial energy deficit and result in significant weight loss.

5) Metabolic benefits

In my opinion, it is still unclear whether low carbohydrate diets offer significant benefits over a calorie-equated higher carbohydrate diet in those who do not struggle with blood sugar control.

That being said, I do think there may be benefits to those who are at risk of developing or already have diabetes. The findings of one study in particular suggest that low carbohydrate diets result in increased insulin sensitivity and more favourable triglyceride levels compared to low fat diets, even when total weight loss was accounted for.

However it is important to point out that the differences we are talking about here aren’t huge and that well-controlled diet studies tend to be short in duration – this makes long term effects hard to identify. Something that is often overlooked is that as an individual who diets and becomes more insulin sensitive will likely be able to ‘handle’ more carbohydrates. As I mentioned, one of the key benefits to low carb diets for those who have poor blood sugar control is increased insulin sensitivity. However, once insulin sensitivity has increased up to a point, a low carbohydrate diet may cease to offer a unique benefit over and above calorie restriction.

Take home points:

  1. One diet does not suit everyone, and finding which diet you can stick to and enjoy long-term is likely far more important than any small benefit you may get from opting for a low carbohydrate diet.
  2. Further to this, as you lose weight and increase your metabolic health you may no longer benefit from a low carbohydrate diet in the same way you originally did.
  3. For this reason there may be some merit in starting with a low carb diet and then introducing more carbs as your blood sugar control increases.
  4. Note that you will still have to be in an energy deficit to continue to lose weight. However, by this stage you may be looking to maintain your new healthy weight in a sociable and non-restrictive way which you can adhere to long term.

The idea that there is only one diet that will work for you or that the diet that initially worked for you is the one you have to stick to forever needs to die.

Is a low carb diet for you?

* Enjoy might be the wrong word here… What I really mean here is: is low carb dieting an easy way for you to create an energy deficit? It is unlikely anyone is going to ‘enjoy’ dieting, but do you find low carb dieting the lesser of the various evils? Does it fit into your life easily? Do you feel good? Can you see yourself sticking to it long term?

** The research suggests a small additional benefit in terms of weight loss and insulin sensitivity. However, these results may be short term (most studies are relatively short in duration and you tend to find that the longer the study, the less control the researchers have – so it is somewhat of a balance between a well-controlled study and the length of intervention). It is as yet unclear whether the additional benefits of low carb diets for those at high risk of cardiovascular disease, obesity and diabetes persist long term. It would seem plausible and likely that as weight loss occurs and improvements in glucose control are realised, the unique benefits may no longer be evident.

The 5 Biggest Mistakes People Make with Low-Carb Diets

1) Thinking calories don’t matter

First and foremost, you need to understand that low carbohydrate diets work the same as any other weight loss diet – by creating a calorie deficit. Lowering your carbohydrate intake doesn’t mean you can eat as much as you want as long as you avoid carbohydrates. You still need to be in an energy deficit to lose weight.

Many low carb advocates get a bad name because they fail to understand this concept and state that calories don’t matter as long as you keep carbohydrates and thus insulin – the body’s main storage hormone – low. I won’t go too much into this here as this could be a topic in itself. But briefly, many low carb advocates believe low carb diets work because they reduce levels of insulin. This is patently false, and James Krieger has written a fantastic series explaining exactly why.

2) Eating excessive amounts of fat

A.k.a. putting butter in your coffee, sucking on spoons of peanut butter or just outright becoming an avocado. This links into my first point- if you over-eat fat and are no longer in a calorie deficit, your low carbohydrate diet will not result in weight loss. I feel this deserves its own point as this is often where people go wrong.

3) Going to extremes

Over restricting carbohydrates to the extent that you are depriving your body of key nutrients by avoiding fruits and vegetables. Yes, fruit and veg contain carbs, but they also have vitamins, minerals and fibre in. They are also relatively tasty, and most are pretty low in calories making them a good choice in any weight loss diet.

I’ve also heard of people avoiding brushing their teeth for fear of putting them out of ketosis (a state in which there is not enough glucose to be used for energy).

Focus on creating an energy deficit rather than trying to micromanage your metabolism. The deficit will take care of that.

4) Trying to perform strenuous endurance exercise on a low carbohydrate intake

Any exercise that involves high intensity efforts over a relatively long duration will be negatively affected by low carbohydrate availability, due to the energy systems involved.

If you are exercising purely to aid weight loss and improve health then crack on. If you are performance-minded then you’re going to want to eat some carbs and give your muscles some glycogen!

5) The temptation to tell everyone you meet about how your diet is great and how they should try it too

Please, don’t.

Take Home Points

  • It is unlikely we will ever find one diet that is ‘optimal’ for everyone.
  • Dieting success is far more psychological than we give credit.
  • Dieting success has been achieved with high and low carbohydrate diets and both have been used to reduce obesity related co morbidities such as cardiovascular disease and diabetes.
  • To give low carb diets their full credit, they have been shown to induce greater weight loss and metabolic health compared to low fat diets in the short term but more research is needed to establish whether these benefits persist long term. It also remains unclear whether the benefits are worth it. At the moment, the evidence is not compelling enough to encourage the use of low carb diets over other potentially more enjoyable and sustainable ways to lose weight.At the end of the day, the biggest predictor of weight loss success is the ability to stick to your diet and as such this should factor heavily when choosing a diet.