Ask a nutritionist: Should I do the keto diet to lose weight?

Question:

I’m a woman in my late 30s and I want to lose about 50 pounds. I’ve tried a number of different diets and weight loss programs over the years and my weight has yo-yo'd. I’ve been hearing and reading a lot about the keto diet being good for weight loss, but I’m worried it’s just another fad diet. Is keto something I should try, and do you have any tips for making this work for me? —Shelby M.   

Answer: 

Dear Shelby, 

Navigating through the myriad of diets and weight loss programs can be overwhelming, especially for those who have experienced the frustrating cycle of weight fluctuations. Finding a dietary pattern that works with your lifestyle and preferences is key for long-term success.  

While the keto diet has gained popularity over the last few years, and many have disregarded it as just another fad, there’s actually extensive published peer-reviewed evidence on the benefits of this approach.

When it comes to weight loss, research has shown that the ketogenic diet (aka keto) can be a very effective tool. ^1,2 Studies indicate that people following a keto diet typically experience decreased insulin and blood sugar levels, facilitating weight loss without the need for calorie counting. ¹

Furthermore, there's evidence to suggest this dietary pattern could help with the following: ² 

• Curbing hunger hormones 
• Decreasing the fat around your organs (visceral fat), which is more harmful that the fat underneath your skin (subcutaneous fat) 
• Preserving muscle mass as well as resting metabolic rate (RMR) when losing weight 

Conventional calorie-restrictive diets often lead to a decline in RMR due to muscle loss. This can worsen your metabolic health and leave you needing further calorie reduction to lose weight and keep it off. 

On the other hand, the keto approach has emerged as a promising solution, relieving these concerns by preserving muscle mass and sustaining RMR. ^1,3 

When we’re surrounded by carbs and sugar-laden temptations, transitioning to a keto diet can be challenging. For some people, rather than attempting a drastic overhaul overnight, it may be more manageable to gradually reduce carb intake while exploring new ways to diversify their plates with more protein and vegetables. 

Research has found that diets that reduce carbohydrates modestly and focus on low glycaemic index (GI) carbs are successful at supporting weight loss as well. ^4,5 

What is the keto diet? 

The keto diet is a dietary pattern that’s low in carbohydrates, high in fat, and contains moderate amounts of protein. 

For most people using this dietary approach, a typical distribution of these macronutrients is around: ⁶ 

• 55-70% fat  
• 20-35% protein  
• 5-10% carbohydrates 

Here’s what one day of following a keto diet might look like compared with a standard Western diet: 

When glucose from carbs is in short supply, your body turns to fat as an alternative energy source in a process called ketosis. This includes the fat you eat as well as the fat stored in your body. Your liver turns this fat into chemicals called ketones, which your body can then use for energy. 

You can learn more with our essential guide to the ketogenic diet.  

Transitioning to a keto diet 

If you’re looking to try a keto diet, it’s important to find an approach that works for you. Are you someone who likes to rip off the plaster and dive right in? Or would you rather dip your toe in the water first before jumping into the deep end? 

If you’re in the former camp, the most important steps are: 

• Getting rid of carb-based foods (like rice, pasta, potatoes, and most fruits) 
• Stocking up on protein and vegetables 
• Making sure you’re adding sodium (aka salt) to your foods and drinking plenty of water to replace what your body loses through ketosis 

If you’re someone who wants to ease your way in, here are some easy steps to take: 

Reduce or swap carbs 

Reducing or swapping carbs is the initial step for those easing into a ketogenic diet. This can involve gradually replacing high-carb foods with lower-carb alternatives. 

Here are some ways you might do this: 

• Opt for leafy greens and non-starchy vegetables instead of starchy veg like potatoes, peas, and corn. 
• Try out cauliflower rice or courgette noodles instead of some or all of your usual rice and pasta. 
• Swap out high-carb snacks like pretzels, crisps, and crackers for protein-based snacks like string cheese, jerky, or Greek yoghurt. 

Additionally, since your goal is weight loss, be mindful of popular “keto” products that are now popping up on supermarket shelves. Not only are they ultra-processed and may lead to overconsumption of calories, ⁷ many of them also add in fake fibres and other ingredients that are not truly “low carb” and can still induce an insulin and glucose response.  

Focus on protein 

Protein-rich foods not only help to promote feelings of fullness and satiety, but also play a crucial role in preserving muscle mass, especially during weight loss. ⁸ 

Additionally, including more protein in your diet can help balance glucose levels and support overall metabolic health. ^9,10

Try to include a source of protein at every meal. Focusing on 25-30 grams (g) of protein for meals and around 10-15 g for snacks will help with transitioning to a lower-carb approach. 

Opt for animal-based protein sources, which are low in carbs, like eggs, meat, fish, and cheese. If looking for plant-based sources, choose ones that are lower in carbs like tofu, hemp seeds, chia seeds, and tempeh.  

Try new vegetables 

When reducing carbs, embracing new vegetables can be a great way to not only add diversity to meals but also ensure you are getting essential nutrients. 

Incorporating low-carb vegetables will enhance the nutritional profile of your meals and help to keep you satisfied while keeping carb counts in check. Good options include: 

• Spinach 
• Kale 
• Broccoli 
• Courgette 
• Cauliflower 
• Bell peppers 

While vegetables themselves are typically low in fat, they can also be a great vehicle for extra fat in your diet. Finding new ways to add fat to your meals is important on a keto diet, and you can easily bump up your intake by cooking veg with healthy fats or pairing them with high-fat dressings and dips. 

Experimenting with different cooking methods such as roasting, grilling, or sautéing can enhance the flavour and texture of many different vegetables. Challenge yourself to buy a new vegetable at the shop each week until you find some new favourites. 

Stop fearing fat 

Contrary to conventional wisdom, dietary fat is not to be avoided. In fact, it’s a crucial component to a ketogenic approach, serving as the primary source of energy in the absence of carbohydrates. 

Restricting fat in your diet can leave you feeling hungry and lead to eating more carbs, the exact thing you are trying to reduce. 

And despite popular belief, dietary fat does not cause weight gain or heart issues. ¹¹ Instead, it provides crucial fat-soluble vitamins like A, D, E, and K. 

Start to incorporate sources of healthy fat into your meals, such as: 

• Avocados 
• Nuts 
• Seeds 
• Olive oil 
• Coconut oil 
• Fatty fish, like salmon, tuna, or sardines 

Cooking vegetables in avocado oil, using olive oil as a dressing on your salads, or buying fattier cuts of meat and fish are all great ways to include more fat in your diet.  

As you experiment, you may find that you’re successfully managing your weight by cutting back on carbs without needing to get into the levels that induce ketosis. Many people can see success with the implementation of a low-carb approach, typically defined as less than 150 g of carbs per day. ² However, the principles remain the same: reduce carbs (especially high-GI and processed carbs), focus on protein and veg, and don’t fear fat. 

A final note from a Lingo nutritionist 

The keto diet may be a big lifestyle change for some since it’s much different than the typical Western diet. Staying with a keto diet often requires a bit of planning, but don’t get discouraged if it takes some time to adapt to this new way of eating or you fall off course on some days.  Your overall eating pattern is more important than one day. 

While the keto diet may not be the right approach for everyone, it’s a way of eating that could make a difference to your health with proper guidance and support. ¹² 

If you find success with this dietary approach, it’s important to be mindful of what you decide to do after the weight has come off. 

Going back to the same level of carbohydrates you were eating before will likely lead to weight regain. However, many people find that they can start to play around with carbs to find the sweet spot of what their body can handle: their own personal carb tolerance. 

While carb tolerance is not a medically accepted term, some often use it to refer to an individual’s metabolic response to eating carbohydrates. In the most basic terms, carb tolerance is the number of carbs you can eat while keeping weight stable and glucose steady. 

Once you’ve reached a weight you are happy with, you may decide to start adding small amounts of higher-carb foods like starchy vegetables, fruit, or whole-grains. It’s advisable to start slow and pay attention to how you’re feeling. Do your energy levels remain steady? And are you getting hungrier or tired after meals? 

Using a continuous glucose monitor (CGM) like Lingo can also help you see in real time how additional carbohydrates are impacting your glucose levels. If you’re seeing large spikes after eating more carbs and noticing more hunger or changes in energy levels, you may be over your carb tolerance. 

— Sarah Koenck, Registered Dietitian and Nutritionist 

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