Understanding The Science Behind The Keto Diet

The keto diet is a high-fat, low-carb, moderate-protein diet that has gained popularity as a weight loss method. The goal is to replace glucose calories with fat. In a typical keto diet, fats make up 60% to 80% of daily calories, proteins make up 15% to 20%, and carbs are restricted to no more than 50 grams. This diet aims to send the body into a state of 'ketosis', where it burns stored fat for energy instead of carbohydrates.

What is the keto diet?

The ketogenic diet, or keto, is a high-fat, moderate-protein, low-carbohydrate diet. It has been around since the 1920s, originally recommended by doctors to help with conditions like epilepsy and diabetes.

The keto diet involves eating plenty of foods that are high in fat, such as avocado, egg, and haloumi. The aim is to swap out glucose calories with fat. In a typical keto diet, fat will make up 60% to 80% of your daily calories, proteins 15% to 20%, and carbs are restricted to no more than 50 grams. This makes it a very restrictive diet.

The goal of the keto diet is to send the body into a state of 'ketosis', where it burns stored fat as a source of energy instead of carbohydrates. When you're on the keto diet, you're eating too few carbs to support your body's energy needs, so your body turns to burning your stores of body fat for fuel. As your body burns body fat for fuel, it produces ketones—substances made in your liver. Your body enters the metabolic state of ketosis within about four days of starting the diet.

There are several types of keto diet, including the standard ketogenic diet (SKD), the cyclical ketogenic diet (CKD), the targeted ketogenic diet (TKD), and the high-protein ketogenic diet (HPKD). The SKD and HPKD are the most common and have been the most researched.

The keto diet has been highly effective for certain conditions, especially type 2 diabetes. It has also been linked to other benefits, including improved cognition in people with Alzheimer's disease, improved blood sugar control, and weight loss.

However, the keto diet is not suitable for everyone. It may be harmful if followed incorrectly or without proper supervision. It can also be challenging to maintain due to its restrictive nature, and it may affect social events as eating out becomes more difficult. It can also be hard to get the right nutrients as it cuts out many nutrient-dense and fibre-rich foods.

Before starting the keto diet, it is important to talk to your doctor or a nutritionist to ensure it is right for you and to come up with a tailored meal plan.

How does the keto diet work?

The keto diet is a high-fat, moderate-protein, and low-carbohydrate diet. It involves eating a very low amount of carbohydrates, with fat making up anywhere from 60% to 80% of your daily calories, proteins making up 15% to 20%, and carbs restricted to no more than 50 grams. The goal is to send the body into a state of 'ketosis', where it burns stored fat for energy instead of carbohydrates.

The keto diet was originally used to treat drug-resistant epilepsy in children, but it has since become a popular weight loss method. Studies show that those who follow the keto diet are more likely to lose weight within the first 3 to 6 months than those who follow a more balanced diet. However, because the keto diet calls for drastic changes in daily eating habits, it's best to consult a doctor or nutritionist before starting.

When on the keto diet, you eat very few carbs, which are typically broken down by the body into glucose to provide energy. With a restricted carb intake, your body turns to burning stored body fat for energy, producing substances called ketones in the liver and entering a metabolic state called 'ketosis'. This process can cause a range of side effects, commonly known as the "keto flu", including stomach aches, diarrhoea, trouble sleeping, and poor concentration.

The standard ketogenic diet (SKD) is the most common and well-researched type, consisting of 70% fat, 20% protein, and 10% carbs. There are also less common variations, such as the cyclical ketogenic diet (CKD), which involves periods of higher-carb intake, and the targeted ketogenic diet (TKD), which allows for more carbs around intense workouts.

To follow the keto diet, it's important to include plenty of non-starchy, low-carb vegetables like kale and spinach, as well as high-fat foods such as avocado, eggs, and fatty meats. Carbohydrate intake should be restricted to 20-50 grams per day, which means eliminating bread, pasta, rice, cereals, starchy vegetables, most fruits, and sugary drinks.

The keto diet has been shown to have several potential benefits, including weight loss, improved blood sugar control, and increased insulin sensitivity. However, it may also have negative consequences, such as an increased risk of heart disease due to higher saturated fat intake, and difficulty maintaining the diet due to its restrictive nature. It's important to consult a healthcare professional before starting the keto diet to ensure it is safe and appropriate for your individual needs and health status.

What are the benefits of ketones?

Ketones are molecules produced in the liver from fats when glucose is limited. They are an alternative fuel source for the body and brain. Here are some of the benefits of ketones:

• Weight Loss: Ketones can help with weight loss by reducing hunger and increasing satiety. Research shows that ketogenic diets are effective at promoting weight loss.
• Increased Energy: Ketosis, the metabolic state where the body burns fat for energy instead of glucose, can lead to increased energy levels.
• Improved Brain Function: Ketones have been found to improve cognitive function, especially in people with Alzheimer's disease. They are the brain's only significant alternative fuel source and can become the primary fuel in conditions of limited glucose availability.
• Disease Treatment and Management: Ketones have been shown to be effective in treating and managing various diseases, including epilepsy, type 2 diabetes, and some forms of cancer, metabolic and cardiovascular disease, and neurological disorders.
• Reduced Inflammation: Ketosis can reduce inflammation and has been linked to improved brain function and a lower risk of chronic illnesses.

How to follow the keto diet?

To follow the keto diet, it's important to understand the basics. The keto diet is a high-fat, low-carbohydrate, and moderate-protein diet. The goal is to reach a metabolic state called "ketosis", where your body burns stored fat for energy instead of carbohydrates. This can lead to weight loss and have other potential health benefits. Here are some guidelines on how to follow the keto diet:

• Before starting the keto diet, consult with your doctor or a nutritionist to ensure it is safe and suitable for you. Get clearance from your healthcare team, especially if you have any health conditions or dietary restrictions.
• Focus on liver-supportive foods like garlic and onions before starting the diet, as the liver works hard to produce ketones. Reduce your intake of sugar, caffeine, and alcohol.
• When following the keto diet, include plenty of non-starchy vegetables, such as kale and spinach, which are low in carbohydrates but provide valuable vitamins and minerals.
• Consume high-fat meats, processed meats, fish, oils, lard, butter, nuts, high-fat dairy (e.g., cheese), and low-carb vegetables such as leafy greens. Specific fruits like avocado are also allowed.
• Avoid all bread, pasta, rice, cereals, conventional baked goods, legumes, beans, root vegetables, most fruits, and starchy vegetables like potatoes.
• Be mindful of your drink choices. Avoid fruit juices, fizzy drinks, cordials, and milk-based drinks. Opt for water, unsweetened coffee or tea, and low-carb liquors like vodka or tequila mixed with soda water.
• Plan your meals ahead of time and stock up on keto-friendly foods. Prepare and cook in batches to make it easier to stick to the diet.
• Be cautious of hidden carbs and read food labels carefully. "Net carbs" on food labels refer to the amount of carbs absorbed by the body and can be calculated by subtracting indigestible carbs from total carbs. However, this calculation is not always reliable.
• Consider using keto-friendly snacks and meal replacements to help manage hunger and stick to the diet.
• Monitor your progress and make adjustments as needed. The keto diet may not be suitable for everyone, and long-term compliance can be challenging due to limited food choices and social restrictions.

What foods are allowed/avoided on a ketogenic diet?

Foods to Eat on a Ketogenic Diet

The ketogenic diet is a high-fat, moderate-protein, and very low-carbohydrate diet. Carbohydrates are the body's preferred source of energy, but on a strict ketogenic diet, about 5% to 10% of energy intake is from carbohydrates. The reduction of carbohydrates puts the body into a metabolic state called ketosis, where the body starts breaking down stored fat into molecules called ketone bodies to use for energy without circulating blood sugar from food.

Animal Proteins

Fish and shellfish are keto-friendly. Salmon and other fish are carb-free and rich in B vitamins, potassium, and selenium. Salmon, sardines, mackerel, and other fatty fish are also high in omega-3 fats, which have been linked to lower insulin levels and increased insulin sensitivity. Meat and poultry are also considered staple foods on the keto diet as they contain no carbohydrates and are rich in B vitamins and minerals.

Eggs

Eggs are an extremely healthy protein source as each large egg contains less than 1 gram of carbs and about 6 grams of protein. They also contain antioxidants such as lutein and zeaxanthin, which protect eye health.

Dairy and Dairy Alternatives

Cheese is very low in carbs and high in fat, making it an excellent fit for the keto diet. Plain Greek yogurt and cottage cheese are also nutritious, high-protein foods. While they contain some carbs, they can be eaten in moderation on keto. Cream and half-and-half are also very low in carbs and high in fat, making them ideal for keto.

Plant-Based Milk

Unsweetened soy, almond, and coconut milk are keto-friendly. Sweetened options have too much sugar to be considered appropriate.

Green Leafy Vegetables

Green leafy veggies are extremely low in carbs and rich sources of vitamins, minerals, and antioxidants. In particular, dark leafy greens like spinach, kale, and collard greens are packed with vitamin K and iron.

Peppers

Peppers are a rich source of vitamin C. For instance, one bell pepper provides 107% of the daily value (DV) for vitamin C.

Summer Squash

Summer squashes, such as yellow squash and zucchini, are extremely versatile and low in carbs. Using a spiralizer, you can make zucchini noodles, which are an excellent substitute for pasta or noodles.

High-Fat Veggies

Avocados and olives are unique among vegetables as they’re fairly high in fat and low in net carbs.

Other Non-Starchy Vegetables

Low-carb veggies make great substitutes for high-carb foods. For instance, you can turn low-carb cauliflower into cauliflower rice or mashed cauliflower. Spaghetti squash serves as a natural alternative to spaghetti, and low-carb root veggies such as jicama and turnips make great substitutes for roasted potatoes or french fries.

Other Plant-Based Foods

Nuts and seeds are healthy, high in fat, and low in carbs. Berries, particularly raspberries and strawberries, are also low in carbs and high in fiber. Dark chocolate and cocoa are delicious sources of antioxidants.

Oils

Olive oil is high in oleic acid, a monounsaturated fat that has been found to decrease heart disease risk factors. Coconut oil is high in saturated fat but contains medium-chain triglycerides (MCTs), which can increase ketone production.

Unsweetened Coffee and Tea

Coffee and tea are healthy, carb-free drinks that have been shown to have a significantly reduced risk of diabetes.

Foods to Avoid on a Ketogenic Diet

Refined Carbs

Eating refined high-carb foods like white bread, pasta, rice, and pastries could prevent a ketogenic state.

Alcoholic Drinks

Beer, liqueurs, and mixed liquor-based drinks have a high carb and low nutrient count, which makes them foods to avoid on a keto diet. Lower carb drinks — like dry red or white wine or hard liquor — will be your best bet if you want to imbibe a drink.

Honey and Syrups

Honey and syrups like agave or maple are concentrated sugar. They contain little else and can easily increase your daily carb count.

Fruit Juice

Juice is high in naturally occurring sugar and lacks dietary fiber. This is problematic, as fiber is needed for proper digestion and can be tricky to get enough of on the keto diet.

Soft Drinks

Sodas are essentially bubbly sugar water that provides zero nutrition and a high carb count.

Condiments

Ketchup, barbecue sauce, and sweet chili sauce are sugar-packed condiments that don't provide much in terms of nutrients or fiber.

Glazed or Honey-Baked Ham

The sugar baked onto or infused into these sweetened hams can keep you from reaching or maintaining ketosis.

Light or Low-Fat Margarine

Light or low-fat margarine skimps on the fat — your main source of fuel on the keto diet.

Dried Fruit or Trail Mix

When fruit is dried, its sugar is concentrated into smaller serving sizes. While dates are nutritional powerhouses, they concentrate too much sugar to reasonably be part of a keto diet.

Low-Fat Diet Foods

Foods marketed as low fat tend to be higher in sugar to compensate for the lack of fat. Common reduced-fat foods that are instead high in added sugars include low-fat or fat-free yogurt, low-fat or fat-free mayonnaise, low-fat salad dressings, reduced-fat peanut butter, and reduced-fat or skim milk.

Starchy Vegetables

White and sweet potatoes, peas, corn, beets, and carrots ought to be avoided on the keto diet because of their high-carb content.

Sweetened Yogurt or Dairy

When adding dairy to your diet, steer clear of flavored or sweetened varieties, which will add to your carb count. This is especially common in flavored yogurt and cottage cheese.

Certain Fresh Fruits

Fruits like mangoes, bananas, and grapes are naturally higher in carbs. While delicious and nutrient-dense, they could keep you from reaching or maintaining ketosis.

Beans and Other Legumes

Legumes like beans, lentils, and chickpeas may be challenging to incorporate into your keto diet as they are high in carbs.

Quinoa and Other Grains

Grains like quinoa and millet are too high in carbs to become a staple in your keto diet.

Frequently asked questions