The ketogenic diet (or keto for short) is one of the hottest global dietary trends today. It’s a low-carb, high-fat diet that is believed to have an astounding impact on human health by an ever-growing group of advocates.
How does ketogenic dieting work?
Due to the low carbohydrate intake (and low to moderate protein), the body doesn’t have enough glucose to feed the brain and muscles, so it switches to metabolising fats. The fat is turned into ketones by the liver, which becomes the energy supply for the brain and muscles.
The diet was originally created for use in the treatment of epileptic seizures in children, where it appears to show a beneficial effect. However, these days keto is being promoted predominantly for weight loss (though many advocates also swear that it can have many more benefits). Proponents suggest that it reduces appetite and suppresses hunger levels, thereby achieving rapid weight loss results.
It’s important to remember that ketosis is not the usual body’s metabolic state, as the body tends to prefer carbohydrates as a source of energy (especially the brain), and ketosis is reserved as a response to starvation or other extreme circumstances. Therefore, there is some concern that the diet may have some long-term adverse effects.
Moreover, this diet does not focus on high protein intake (like many other low-carb diets), but rather suggests that fats provide up to 80% of daily energy (calories) to the body! This may restrict a person’s diet to the point where nutrient deficiencies become likely.
When Does It Become Unhealthy?
Keto may seem like an attractive prospect for losing weight quickly and easily, but what’s the price we’re willing to pay, and how long will the weight loss results last?
Keep in mind that when your body enters ketosis, it essentially enters “starvation mode”. Although a carefully followed keto diet should preserve muscle, it may hamper efforts to gain muscle. A poorly followed keto diet could lead to muscle wastage, due to not obtaining enough amino acids. This, in turn, could actually make keeping weight off in the future more difficult. Lean mass (from muscle) is important for keeping the metabolism working quickly. Being in “starvation mode” may also cause the body to attempt to hold onto its fat stores. This means that rebound weight gain may be more likely, and it can take a lot of effort to restore any lost muscle mass!
You should be aware that prolonged ketosis may lead to:
1. A slowing down of fat loss.
2. An increased risk of developing type 2 diabetes – As suggested by some studies.
3. Dehydration – Much of the initial rapid weight loss is due to a loss of significant quantities of water.
4. Gastrointestinal discomfort – Constipation, diarrhoea (more dehydration!), flatulence, bloating.
5. Possible increased risk of developing hypothyroidism or thyroid malfunction.
6. Serious side effects – Such as metabolic acidosis, hypoglycaemia, fainting, and hypercholesterolemia (usually from taking the diet to an extreme).
7. Increased arterial stiffness – May increase risk of cardiovascular disease.
8. Other harmful side effects in individuals carrying specific errors in the CPT2 gene, compromising liver function from an inability to metabolise ketone bodies.
In a Nutshell
It may certainly be possible to lose weight by going keto, but it could also have detrimental effects on our body, and any weight loss achieved may not be sustainable. Following a restrictive diet such as keto for the long term is usually not advisable!
Whilst extreme diets may seem tempting as quick-fix weight loss solutions, the weight may soon begin to creep back on, and the body may have suffered some serious side-effects in the process (muscle loss and dehydration, to name but a few). In addition, yo-yo diets which lead to weight loss fluctuation can have detrimental effects on health and are associated with increased mortality (risk of death).
It is always recommended to make slow and sustainable lifestyle changes which will help you lose weight and keep it off, as well as build towards your long-term health goals (and always include physical activity). If you are undertaking the keto diet, it's important to also seek medical supervision, to ensure you aren’t suffering from any adverse side-effects, or putting yourself at risk of nutrient deficiencies.