© iStockHigh fat low-carb breakfast with eggs, tomato, avocado, bacon and blueberries. iStock
Looking for a science-backed way to lose weight or boost your health? The decades-old high-fat, low-carb diet (HFLC), otherwise known as the ketogenic diet, has exploded in recent years with everyone from the Kardashians to our own Today host Karl Stefanovic giving the keto trend a whirl.
Developed in the 1920s by researchers at Johns Hopkins University, the ketogenic diet was originally created as an effective protocol for helping patients to manage epilepsy symptoms. Evidence reported in the European Journal of Clinical Nutrition suggests that very-low-carbohydrate ketogenic diets could play a therapeutic role in numerous diseases.
While there's a good amount of evidence that shows that a HFLC diet is beneficial in a clinical setting, its use as a weight loss tool is a more recent development, and while celebrities seem t =o be singing its praises, critics are divided about it. Here are some of the pros and cons of a ketogenic diet - and how you can try it out for yourself.
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How does the keto diet work?
The purpose of the ketogenic diet is to switch our bodies from burning carbohydrates for fuel to burning ketones instead. Ketones are formed in the liver when the body is starved of carbohydrates.
Typically, when food is consumed, it's turned into glucose that the body uses for energy. When you cut carbohydrates, your body has to seek other sources of fuel. For this, it turns to fat. Fat is processed by the liver and turned into ketones. When this happens, you are in a state of ketosis.
While generally easy to implement, the HFLC diet isn't for the faint of heart. It does require following strict guidelines and careful measurements. For adults, the recommended daily intake of net carbs (total carbs minus fibre) is only about 25 to 30 grams. To put that in perspective, half a hamburger bun has 20 net carbs.
It also allows for a low amount of fibre - only 5 per cent - and a high amount of fat, which should account for almost 70-80 per cent of your daily calories.
Leading Australian dietitian Susie Burrell warns that although it can result in quickly shedding kilos, there are likely more sustainable ways to approach dieting if weight loss is your goal.
"It is not easy to achieve keto - there are very few foods to work with to achieve a 70 per cent fat diet which makes adherence and long term sustainability difficult," she tells 9Honey. "Keto is also particularly low in dietary fibre and calcium."
While the diet messaging is simple - increase your consumption of healthy fats, and cut down or remove carbohydrate-rich foods from your diet - the logistics of it is far more involved, and requires understanding and precisely tracking your macronutrient ratios.
There is a cheat's version of the diet known as "dirty keto", that takes a more relaxed approach to the rules, allowing for the occasional processed or fatty food, though experts have largely condemned it for its tendency to cut nutrients out of an already restrictive diet - not to mention, the likelihood of maintaining a state of ketosis while eating high calories, processed foods is low, according to Burrell.
"The calories and proteins are likely to take you out of ketosis unless you are an especially large frame, meaning your dirty keto diet will be more likely to be contributing to weight gain rather than fat loss."
Now for the big question: which foods can you eat?
Foods to enjoy and those to avoid on a ketogenic diet
What qualifies a food as keto? What exactly does a HFLC diet look like? Keto apostles can choose lots of healthy fats, for up to 80 per cent of your total calories. Think olive oil, butter, ghee, nuts and seeds, as well as animal fats like lard and schmaltz. You should also include lots of non-starchy vegetables.
Eat plenty of:
- Healthy fats and oils
- Organic animal protein, grass-fed beef, lamb, venison
- Poultry, chicken, turkey, duck
- Organ meats and offal
- Fish, bass, tuna, trout, salmon
- Cage-free eggs
- Leafy greens: collards, kale, arugula
- Non-starchy vegetables: broccoli, celery, zucchini, leeks
- Medium-carb vegetables: green beans, tomato, bell pepper, snap peas
- Fresh herbs
- Fatty fruits like avocado
- Spices and seasonings
- Bone broths
Eat a moderate amount of:
- Full-fat dairy and hard cheeses, goat and cow milk
- Fruits and berries: strawberries, raspberries, blueberries
- Medium starchy vegetables: potatoes, peas, yams
- Beans and legumes: chickpeas, lima, black, hummus, lentils
- Soy products: tofu, tempeh, edamame
- Sweeteners like Stevia or Erythritol
- Nuts and seeds
- Condiments: pickles, mustard, hot sauce
- Black coffee and unsweetened tea
- Sweeteners: artificial or natural, honey, agave, dextrose, lactose
- Corn and all foods containing corn derivatives
- Flour and breads: bagels, muffins, pasta, bagels
- Candy and desserts
- Premade or pre-packaged foods: soups, broths, boxed meals
- Sweetened beverages including soda or coffee drinks
- Fruit juices
- Grains: rice or cereal, crackers, chips, pretzels, oatmeal
- Processed foods
- Beer, wine or hard alcohol
- Anything that will cause a spike in blood sugar
A typical ketogenic diet day
With a little planning, making healthy choices throughout the day should come easily. Aim for 20-30 net carbs, lots of fats and a moderate amount of protein. Drink lots of water and continue to stay hydrated. A typical meal plan might look something like this:
Pick something quick, easy and delicious. For a hot meal, make a quick scramble with cage-free eggs, bell peppers, and spinach. If you're on the go, try a chocolate chia seed pudding with full-fat coconut cream, raw cacao and cinnamon.
Get a little protein with grilled chicken or salmon, and add avocado and a leafy green side salad. Slather it all with a heart-healthy dose of extra virgin olive oil.
Munch on a hard-boiled egg with salt and paprika, a ripe avocado or a handful of roasted nuts.
Get a little creative with your typical meat and potatoes. Choose a rich, fatty cut of meat, ribeye or pork chop and serve with an herb-filled gremolata. Instead of potatoes, whip up a cheesy cauliflower mash.
Pros and cons of a ketogenic diet
There are lots of good reasons that a high-fat, low carb diet might be right for you. Some of the pros include:
- Eating a ketogenic diet reduces insulin and in turn can lead to lower levels of inflammation.
- It can lead to weight loss. This is especially true at first. This is partially because of better blood sugar stabilisation. A lack of highs and crashes means less snacking throughout the day, and eating more fats means you feel full longer.
- Eating keto means consuming less sugar. The Australian National Health and Medical Research Council recommends limiting intake of foods and drinks containing added sugars, as they can increase blood pressure and weight gain along with the likelihood of developing chronic illnesses. Weight gain also places increased strain on key organs such as the heart and kidneys.
- You'll eat more healthy fats. Consumption of healthy fats supports your metabolism by providing slow, steady energy, assists with hormone production and cell signalling, and the absorption of nutrients.
Along with the pros, there are also some cons of the HFLC diet:
- It's hard to start. Doing a keto diet correctly means doing a lot of legwork. Calculating your carbs, fats and intake can be difficult.
- It may not lead to long-term weight loss. While the keto diet might start with a drop on the scale, once your body reaches equilibrium, the numbers should even out. This can be discouraging to some, if weight loss is your main goal.
- The HFLC diet is low in fibre. All that fat and fewer plant-based foods means your body is processing less fibre overall. This can cause a sometimes-unpleasant decrease in digestive health.
- You have to watch your fats. Because this diet relies so heavily on animal-based ingredients, it's important to invest in the best. Make sure you go for organic, grass-fed, cage free animal products whenever possible.
Are you ready to give it a try?
As with all dietary changes, be sure to check with your doctor before starting a new meal plan. The keto diet can be adapted to anyone, so feel free to take baby steps, make a few changes at a time, and see how you feel.