The No-Carb Diet: How Does It Work?

No-carb diets are a recent twist on the long-standing low-carb trend. While low-carb diets restrict carbohydrate intake, no-carb diets aim to eliminate it. No-carb dieters mostly eat animal products, with some allowing for leafy greens like spinach and lettuce.

No-carb diets are popular among people looking to lose weight or help maintain blood sugar levels. However, the weight loss might not be permanent, and no-carb diets can be hard to sustain long-term. They can also lead to nutrient deficiencies, as they are very low in fibre and lack certain vitamins and minerals found in plant-based foods.

No-carb diets are also very restrictive, which can foster an unhealthy relationship with food and lead to disordered eating.

Weight loss

A no-carb diet is an extreme version of a low-carb diet. It involves eliminating almost all carbohydrates from your meals, including whole grains, fruits, and vegetables. While a no-carb diet may be effective for weight loss, it is highly restrictive and may not be sustainable or necessary in the long term. Here are some key points to consider regarding weight loss and no-carb diets:

A no-carb diet can promote weight loss by reducing your overall calorie intake. Carbohydrates are a significant source of energy, and by eliminating them, you may naturally consume fewer calories, leading to weight loss. Additionally, replacing carbs with protein and healthy fats can increase satiety, making you feel fuller for longer and reducing overall calorie intake.

Rapid Initial Weight Loss

No-carb diets often lead to rapid weight loss in the first few weeks. However, this initial weight loss is primarily due to a quick drop in water weight. Carbohydrates hold water in the body, so when you drastically reduce or eliminate carbs, your body releases this stored water, resulting in weight loss on the scale.

Long-Term Weight Loss Considerations

While a no-carb diet can be effective for initial weight loss, it may not be the best approach for long-term weight management. Research suggests that reducing carb intake can be beneficial for weight loss in the first six months, but its effectiveness may diminish over time. Gradually reducing carb intake and focusing on overall calorie reduction may be a more sustainable and less restrictive approach for long-term weight loss.

Health Considerations

No-carb diets can have some potential health benefits, such as improved heart health, better blood sugar control, and reduced belly fat. However, they can also lead to constipation, low energy levels, and insufficient nutrient intake. Completely eliminating carbs may not be necessary, and a more balanced approach that includes a variety of whole foods may be preferable for overall health and sustainability.

Sample No-Carb Foods for Weight Loss

If you decide to try a no-carb diet for weight loss, here are some foods to include in your meals:

• Meats: chicken, beef, turkey, lamb, pork
• Fish: salmon, tilapia, cod, shrimp
• Eggs
• Cheese
• Butter
• Oils: avocado oil, olive oil, coconut oil
• Nuts and seeds: almonds, walnuts, pumpkin seeds, sunflower seeds
• Non-starchy vegetables: broccoli, zucchini, bell peppers, cauliflower, leafy greens
• High-fat fruits: avocado, coconut

Remember, while a no-carb diet may aid weight loss, it is essential to prioritize your overall health and well-being. Consult with a healthcare professional or dietitian to determine the best approach for your specific needs and goals.

Nutritional ketosis

The ketogenic (keto) diet is high in fat, moderate in protein, and low in carbohydrates. The standard keto diet consists of 70% to 80% fats, 10% to 20% proteins, and 5% to 10% carbohydrates. To enter and stay in ketosis, one must stay under 50 grams of carbohydrates per day. This can be achieved in two to four days, although it may take longer depending on factors such as physical activity level and previous diet composition.

Research has shown that nutritional ketosis may have several health benefits, including weight loss, increased energy, and the treatment and management of diseases such as epilepsy, Alzheimer's disease, type 2 diabetes, and heart disease. However, the keto diet can be difficult to follow and may produce side effects such as "keto" breath, constipation, and low bone density.

It is important to note that nutritional ketosis should not be confused with diabetic ketoacidosis (DKA), a life-threatening condition that occurs when the blood turns acidic due to a lack of insulin and an excess of ketones. Nutritional ketosis does not cause a change in the chemical balance of the blood and is not harmful in healthy individuals.

Healthier food choices

A no-carb diet is a very restrictive diet that eliminates carbohydrates as much as possible. This means that all plant-based foods are excluded, as they contain carbohydrates. Instead, dieters can choose from mostly animal products, such as meat, fish, and eggs. Some people following a no-carb diet also eat leafy greens, like spinach and lettuce, as they are very low in carbohydrates.

However, this type of diet can make it difficult to get enough nutrients, especially fibre, which is important for regulating digestion, feeding healthy gut bacteria, and managing cholesterol. It can also be low in certain vitamins and minerals, like vitamin C, potassium, and B vitamins, which are mostly found in plant-based foods.

• Include some plant-based foods: While a no-carb diet restricts carbohydrates as much as possible, including some plant-based foods can provide important nutrients like fibre, vitamins, and minerals. Leafy greens, such as spinach and lettuce, are good choices as they are very low in carbohydrates. Other non-starchy vegetables, like broccoli, cauliflower, and cucumbers, can also be included.
• Choose lean proteins: When selecting animal products, opt for lean proteins like fish, skinless chicken or turkey, and egg whites. These provide protein while being lower in saturated fat, which can increase the risk of heart disease.
• Increase healthy fat intake: Include foods that are high in monounsaturated and omega-3 fats, such as salmon, tuna, nuts, seeds, olives, and avocado. These fats are associated with a lower risk of heart disease.
• Consider taking supplements: Speak to your doctor or a dietitian about taking supplements to ensure you're getting enough nutrients. A good-quality multivitamin and mineral supplement can help fill any nutritional gaps in your diet.
• Be cautious if you have a medical condition: If you have a medical condition, such as diabetes, kidney disease, or a history of eating disorders, consult your doctor before starting a no-carb diet. It may not be suitable for everyone and can, in some cases, be harmful.
• Gradually reduce carbs: Instead of eliminating carbs completely, consider gradually reducing your carb intake. This can help you make a long-term sustainable change and give you time to adjust to a new way of eating.
• Focus on whole foods: Choose unprocessed, whole foods whenever possible. Processed foods, like sweets, sugary drinks, and packaged foods, are typically high in added sugars and unhealthy fats. Opt for whole foods like fish, eggs, vegetables, nuts, and seeds.
• Stay hydrated: Drinking plenty of water is important, especially if you're eating a lot of protein. Water can help with digestion and prevent constipation, which is a common issue on low-carb diets.
• Be mindful of portion sizes: Even when choosing healthier foods, it's important to watch your portion sizes. Eating large amounts of protein and fat can still lead to weight gain and increase the risk of heart disease.

Remember, a no-carb diet is very restrictive and may not be sustainable or healthy for everyone. It's always best to consult with a healthcare professional before making any significant changes to your diet.

Reduced medication

A no-carb or low-carb diet can be beneficial for people with diabetes, as it can help with weight loss and blood sugar control. However, it is important to consult a doctor or healthcare professional before starting such a diet, especially if you are taking medication, as it may be necessary to adjust your dosage.

For people with type 1 diabetes, the strongest evidence suggests that carb counting is the best way to manage blood sugar levels. This involves matching insulin intake to the amount of carbs consumed. There is currently no strong evidence that a no-carb or low-carb diet is safe or beneficial for people with type 1 diabetes, which is why it is not recommended.

For people with type 2 diabetes, a no-carb or low-carb diet can be effective in managing weight, blood glucose (sugar) levels, and the risk of heart disease in the short term. It can also help reduce HbA1c and blood fats such as triglycerides and cholesterol. Evidence suggests that losing weight within 6 years of a type 2 diabetes diagnosis can improve the chances of putting the condition into remission.

If you are taking medication for diabetes, it is important to speak to your doctor or healthcare team before starting a no-carb or low-carb diet, as your medication may need to be adjusted. This is especially important if you are taking insulin or medications that increase the risk of hypos (low blood sugar levels). Additionally, if you are taking SGLT2 inhibitors, such as Dapagliflozin or Canagliflozin, you may need to stop taking them while on a low-carb diet, as they can increase the risk of Diabetic Ketoacidosis.

Improved insulin sensitivity

Improving insulin sensitivity is a key goal for people with type 2 diabetes. Insulin is a crucial hormone that controls blood sugar levels. When the body's cells become less sensitive to insulin, this results in hyperglycaemia (high blood sugar). To compensate, the pancreas produces more insulin, which can lead to a state of hyperinsulinaemia. Over time, this can deplete the pancreas of insulin-producing cells, as seen in type 2 diabetes.

A no-carb diet can help to improve insulin sensitivity by reducing blood sugar spikes. This is because carbohydrates are broken down into glucose, which raises blood sugar levels. By reducing or eliminating carbs, blood sugar spikes are minimised, and the body's sensitivity to insulin is improved.

Several studies have shown the positive impact of low-carb diets on insulin sensitivity. One study involving obese participants with type 2 diabetes found that after 24 weeks, participants lost an average of 9.7 kg and significantly improved their glycemic control, fasting glucose, and HOMA-IR (a measure of insulin sensitivity). Another study, which randomly assigned 164 participants to three weight-loss maintenance diets for 20 weeks, found that a low-carb, high-saturated fat diet improved insulin-resistant dyslipoproteinemia without adverse effects on "bad" cholesterol or inflammation.

While a no-carb diet can be effective in improving insulin sensitivity, it is important to note that this approach may not be sustainable in the long term. Additionally, it is crucial to consider other factors such as adequate fibre intake, saturated fat intake, and the use of artificial sweeteners when following a no-carb diet.

Frequently asked questions