Carb Reduction Vs. Keto: Healthy Balance Or Misguided?

Reducing your carbohydrate intake can be beneficial for weight loss and blood sugar control. However, it's important to note that very low-carb diets like keto can be overly restrictive and may lead to adverse effects if followed long-term. While keto dieters aim for 5-10% of energy intake from carbohydrates, a less restrictive low-carb diet typically allows for 20-130 grams of carbs per day.

The keto diet, a high-fat, moderate-protein, and very low-carbohydrate diet, has been associated with an increased risk of bad LDL cholesterol, which is linked to heart disease. It may also lead to nutrient deficiencies, liver problems, kidney issues, constipation, and fuzzy thinking.

Therefore, it is essential to consult a doctor or dietitian before drastically reducing your carbohydrate intake. A well-planned low-carb diet should include a variety of nutrient-dense foods and prioritize healthy sources of carbohydrates, fats, and proteins.

Weight loss

Reducing your carbohydrate intake can be an effective way to lose weight. Carbohydrates are one of the three main macronutrients in our diets, along with fat and protein. They are an important source of energy and fuel for our brains and bodies. However, cutting down on carbs can lead to weight loss, especially when combined with an increase in protein and healthy fats.

When you reduce your carb intake, your body is forced to use a different type of fuel. Instead of relying on glucose (sugar) from carbs, your body starts burning fat for energy. This process is called ketosis, and it can be triggered by very low-carb diets like keto and Atkins. During ketosis, your liver breaks down fat to produce ketones, an alternative source of fuel for your brain and body.

The number of carbs you should eat per day depends on various factors, including age, sex, body type, and activity level. Generally, a low-carb diet involves consuming fewer than 120-200 grams of carbs per day. However, some very low-carb diets restrict carb intake to less than 50 grams per day to induce nutritional ketosis.

Research suggests that low-carb diets can lead to weight loss, with an average weight loss of about 13 pounds (6 kilograms) within 12 months. Additionally, a low-carb diet may lead to a greater reduction in visceral fat or belly fat compared to a low-fat diet.

Benefits Beyond Weight Loss

Low-carb diets offer several benefits beyond weight loss. They can help lower blood sugar levels, which is especially important for people with diabetes. Low-carb diets also tend to reduce blood pressure and lower insulin levels, a hormone that signals the body to store fat.

Potential Risks

While low-carb diets can be effective for weight loss, they may come with certain risks. Some people following these diets have experienced side effects like kidney stones, vitamin and mineral deficiencies, and increased "bad" LDL cholesterol, which is linked to heart disease. Therefore, it's important to ensure your diet includes a variety of nutrient-dense foods and to consult a healthcare professional before making significant dietary changes.

Nutrient deficiency

Reducing carbs can be beneficial for weight loss in the short term, but it can also lead to nutrient deficiencies, especially on diets like keto, where the percentage of carbs can go as low as 5% of your daily calories. The 2020-2025 Dietary Guidelines for Americans advise getting 45-65% of our daily calories from carbs, and opting for 40% or less can have a major impact on the way our body functions.

Calcium

People on long-term keto diets often lose too much calcium in their urine, in addition to having acidic urine. High-fat diets can increase the amount of acid generated by the body, which the kidneys must filter out to maintain a stable blood pH. This leads to lower urine pH. Calcium from bones is also used to buffer the increased acid production, leading to higher calcium loss in the urine and lower bone density.

Magnesium

Magnesium is another mineral that has been observed to decrease substantially on a long-term keto diet. This mineral is extremely important for our bodies to produce energy, and is required for our nerve cells and brain to function properly. Deficiency has been associated with a wide range of conditions, including heart disease and migraines. Symptoms of magnesium deficiency include muscle cramps, headaches, anxiety, nervousness, and constipation.

Iron

Even though keto diets usually involve eating ample quantities of meat, they also tend to reduce iron levels. Iron is needed for energy production and making red blood cells, and a deficiency can cause fatigue and trouble breathing during exercise. Evidence suggests that iron deficiency may develop on the diet due to reduced absorption of iron caused by high amounts of fat.

Selenium

Research and clinical experience in epileptic children on keto diets have found the diet to decrease selenium levels and cause deficiencies in the long run. High-fat foods tend to be low in selenium, which is why keto diets can lead to lower selenium levels.

Carnitine

Carnitine is a compound made from amino acids that are found in abundant quantities in the heart and muscles. It helps transport fatty acids to the mitochondria, where they are used to make energy. The body can make carnitine, but 75% of our daily requirements come from the diet (mainly from meat and dairy). Because carnitine is needed to burn fat, it’s used up much quicker on a keto diet.

Other Nutrients

Other nutrients that you may be at risk of not consuming enough of when on a low-carb diet include sodium, potassium, and vitamins B and C.

Energy levels

Carbohydrates are the body's primary source of fuel, which it converts to glucose (blood sugar) to generate energy. Slashing your carb intake can, therefore, have a significant impact on your energy levels.

When you eat a low-carb diet, your body enters a state of ketosis, where it starts breaking down stored fat into ketone bodies to generate energy. While this can be beneficial for weight loss, it can also lead to weakness, fatigue, dizziness, and headaches—symptoms often referred to as the "keto flu." This is because your body is trying to adjust to using fat instead of glucose as its primary energy source.

The transition to ketosis can take some time, and during this period, you may experience decreased energy levels and a general feeling of sluggishness. This can also impact your workouts, as you may not feel like you have the strength to exercise as intensely as you used to.

Additionally, if you don't eat enough healthy fats on a low-carb diet, you may not be getting enough energy from your meals. It's important to ensure you're eating enough fat to compensate for the reduced carbohydrate intake.

However, once your body has fully adapted to using fat as its primary fuel source, some people report having more stable energy levels throughout the day, without the blood sugar spikes and crashes associated with a high-carb diet.

It's also worth noting that the quality of the carbohydrates you eat can impact your energy levels. High-quality carbs like sweet potatoes, whole-wheat bread, berries, and quinoa can provide a more sustained release of energy compared to refined carbs like white bread and sugar.

Overall, while a reduction in carbs may lead to decreased energy levels initially, as your body adjusts to using fat for fuel, some people report having more stable energy levels on a low-carb diet over the long term.

Appetite and fullness

Reducing your carbohydrate intake can help suppress your appetite, as carbohydrates assist in regulating your hunger and fullness cues.

A study published in Nutrients in 2022 found that those who consumed more fibre felt fuller and had smaller appetites compared to those who ate less fibre.

However, another study published in Nutrients in 2023 found no difference in appetite between people eating high-fibre and those who didn't.

It is important to note that eating carbs by themselves does not offer lasting fullness like eating carbs with fat or protein. So, combining your carbs with healthy fats or proteins can give you longer-lasting, stable energy and fullness.

Some foods that can help increase feelings of fullness include:

• Eggs
• Greek yoghurt and cottage cheese
• Avocados
• Fish
• Meat and poultry
• Nuts and seeds
• Dark chocolate and cocoa powder
• Shirataki noodles
• Leafy greens
• High-fat veggies like avocados and olives
• Beans and legumes

Health conditions

While reducing carbs can be healthy, very low-carb diets like keto can be overly restrictive and unsustainable in the long run. They can also contribute to adverse effects if followed for a long time.

Weight Loss

Low-carb diets are often used for weight loss. While they can be effective in the short term, the weight will likely return once a normal diet is resumed.

Blood Sugar Control

Low-carb diets can help regulate blood sugar levels, which is especially beneficial for people with diabetes. However, in true ketosis, hypoglycemia is a risk, so it's important to monitor blood sugar levels closely.

Nutritional Deficiencies

Very low-carb diets can lead to nutritional deficiencies, as they restrict fruits, beans, vegetables, and whole grains, which are good sources of vitamins and minerals. This can cause "brain fog", confusion, irritability, and mood swings.

Kidney Problems

Nutritional ketosis may increase uric acid levels, leading to kidney stones or gout flares. While some studies suggest that a keto diet can be safe for people with mild chronic kidney disease under close medical supervision, other studies show that diets high in red meat and low in whole grains, low-fat dairy, and fruit increase the risk of kidney disease.

Liver Problems

The liver has to process a lot more fat on a low-carb diet, which can worsen existing liver conditions.

Heart Health

Very low-carb diets are typically also high in fat, especially saturated fat, which can increase the risk of heart disease. While triglycerides and HDL ("good") cholesterol levels may improve, there is also a risk of increased LDL ("bad") cholesterol.

Constipation

Low-carb diets are often low in fiber, which can lead to constipation.

Frequently asked questions