What if you could eat more and burn fat faster? 2019’s hottest new diet plan says you can.
But is it all it’s cracked up to be?
Want to transform your body into a fat-burning machine? Well, according to proponents of the ketogenic diet, you can.The high-fat, ultra low-carb diet (HFLC) – which has been likened to Atkins and other low-carb eating plans – changes the way your body uses energy, shifting from carbohydrates as a primary fuel source, to fat.
Or, more specifically, ketones.
The ketogenic – or keto – diet lures health-conscious adopters with promises of speedy weight loss, more efficient fat metabolism, improved mental performance and mood, and reduced cravings. Sounds too good to be true, right?
how it works
When you eat high-carbohydrate foods, your body responds by producing glucose and insulin. Carbohydrates are broken down into glucose (sugar), which is the easiest molecule for your body to convert and use as energy. If metabolism was a sport, sugar would always get picked first for the energy team.
When glucose is released into the bloodstream, your pancreas secretes the hormone insulin. Insulin helps keep blood glucose levels in check by signalling for cells to take in those sugars for energy.
Since glucose is being used as the primary energy, fat is not needed, so the body stores it. But by lowering your intake of carbs, your body enters a metabolic state known as ketosis. In this state, you are basically forcing it to use fat as its primary fuel source. Yep, hold the carbs!
WHAT IS KETOSIS
Ketosis is a natural bodily process that helps us survive when food intake is low. In this state, the body switches to using ketones for energy, which are produced from the breakdown of fats in the liver. While the fastest way to get there is by fasting (which is not achievable – or recommended – long term), the aim of the keto diet is to force the body into this state not through starvation of calories, but of carbohydrates. During ketosis, your body runs almost entirely on fat, making it easier to access your fat stores and burn them off.
But what about the brain, you ask? Doesn’t it run on glucose? The brain is incredibly hungry and uses more energy than any other organ in the body, accounting for as much as 20 per cent of the body’s total daily energy needs. While it can’t run on fat directly, as it turns out, the brain – much like the body – can shift to burning ketones, which are a by-product of fat metabolism. Sure, there are some parts of some brain cells that can only burn glucose but, thankfully, there is a process called gluconeogenesis that allows our bodies to convert protein to glucose. That means — you guessed it — protein and fat, not carbs, are key to survival.
KETO FOR BEGINNERS
To reach ketosis, you pretty much have to avoid eating carbohydrates; the fewer the better. And by avoid carbs, we mean a net daily carbohydrate intake of less than 50 grams, or less than 20 if you want to go hard core. So say goodbye to sweet, sugary foods, processed or starchy foods like rice, bread, pasta and potatoes. Sure, giving up bread kind of sucks (what are we going to serve our smashed avo on?), but it’s not like we have to give up all good things.
Thankfully, wine and coffee are allowed. As a general rule, try to aim for foods with less than five per cent carbohydrate content. And don’t make the mistake of replacing carbs with protein as, if protein intake is too high, the body will still be able to defer to using glucose as its primary fuel. A rough guideline is to consume 70 per cent of your daily energy from fat, 15-25 per cent from protein and 10 per cent (or less) from carbs.
THE KETO PANTRY
Sticking to 20 grams per day of carbs seems simple enough, but it’s not like vegetables come with a nutrition label so that you can easily ascertain whether they’re keto-friendly or not.
To reach ketosis, you pretty much have to avoid eating carbohydrates; the fewer the better.
As a general rule, vegetables growing above ground are low carb and get the keto tick of approval, whereas vegetables growing below dirt need to be approached with caution. If you want
to stay in the low-carb safe zone, opt for cauliflower, cabbage, avocado, broccoli, zucchini, spinach, asparagus, kale, green beans and Brussels sprouts.
When it comes to fruit, grapes and
bananas are out, berries and cherries are in. If you want to splurge, raspberries,
blackberries, blueberries, plums, peaches, kiwi fruits, cherries, rock melon and strawberries are your keto-friendliest options. Yay for that!
In the protein category — unprocessed, grass-fed meats are the best. Fish and seafood are generally an excellent option – salmon especially so. And you can go to town on eggs, high-fat cheese and even butter for cooking. And don’t be afraid to splash out on plant-based oils (olive and coconut are great).
SO, IS IT REALLY WORTH GIVING UP PASTA FOR?
If you’re looking for a short-term weight loss solution, the keto diet is sure to provide it. But bear in mind the transition from carb-craving engine to fat-burning machine is not without its challenges. Temporary side effects can range from feeling weak or mentally ‘foggy’ to mild fatigue, flu-like symptoms, headaches and irritability.
It is also important to note that long-term commitment to a keto diet can come with more chronic downsides. Ketones are acidic, with one of their jobs being to pull phosphorous and calcium from bones. So the more ketones you have, the more likely you are to suffer from stress fractures and bone density problems (hello, osteoporosis).
While proponents of the keto diet are evangelical about its weight loss benefits, there is science that suggests it can actually be detrimental for your metabolism. At some stage, if you end up re-introducing carbohydrates, your body will be so excited to see bread, pasta and cheese platters with grapes again that it will cherish them like long-lost friends. Coupled with a slowed metabolism, this could actually make it more difficult to lose weight.
The keto diet also favours high-fat foods, which may not always be the best option for you. The plan is not recommended for people with diabetes as they have a greater risk of developing diabetic ketoacidosis (DKA). As always, if you are considering a diet overhaul, your best bet is to speak with your GP first.