Keto For The Obese: Does It Work?

The ketogenic diet is a high-fat, low-carb, and moderate-protein eating plan that has been advertised as a weight-loss solution. The diet involves drastically reducing carbohydrate intake and replacing it with fat, which puts the body into a metabolic state called ketosis. While the keto diet has been shown to be effective for weight loss, it is not suitable for everyone and may have some negative side effects.

The keto diet can be beneficial for people who are very overweight or obese, as it promotes weight loss by reducing hunger, increasing fat burning, and improving insulin sensitivity. However, it is important to note that long-term studies on the keto diet are lacking, and there may be potential risks associated with the diet, including nutrient deficiencies, liver and kidney problems, and constipation. Additionally, the keto diet can be challenging to stick to due to its restrictive nature.

Before starting the keto diet, it is important to consult with a doctor or dietitian to ensure it is a safe and suitable option for you.

Ketogenic diets and weight loss

The ketogenic diet is a high-fat, low-carb, and moderate-protein diet. It involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbs puts the body into a metabolic state called ketosis, where it becomes incredibly efficient at burning fat for energy.

There is evidence that ketogenic diets can help with weight loss. They may help you lose fat, preserve muscle mass, and improve many markers of disease. Some studies have suggested that a ketogenic diet may be more effective than a low-fat diet for weight loss, even when matching the total calorie intake.

One older study found that people on a ketogenic diet lost 2.2 times more weight than those on a low-calorie, low-fat diet. Triglyceride and HDL (good) cholesterol levels also improved. However, both groups reduced calorie consumption by a comparable amount, which may have increased weight loss.

Another 2007 study compared a low-carb diet to the Diabetes UK's dietary guidelines. It found that the low-carb group lost 15.2 pounds, while the low-fat group lost only 4.6 pounds over three months. However, there was no difference in HbA1c, ketone, or lipid levels between the groups.

• Higher protein intake: Some ketogenic diets lead to an increase in protein intake, which has many weight loss benefits.
• Gluconeogenesis: Your body converts fat and protein into carbs for fuel. This process may burn many additional calories each day.
• Appetite suppressant: Ketogenic diets help you feel full. This is supported by positive changes in hunger hormones, including leptin and ghrelin.
• Improved insulin sensitivity: Ketogenic diets can drastically improve insulin sensitivity, which can help improve fuel utilization and metabolism.
• Decreased fat storage: Some research suggests ketogenic diets may reduce lipogenesis, the process of converting sugar into fat. This is because excess carbs are stored as fat. When there is a minimal intake of carbs, fat is used for energy.
• Increased fat burning: Several studies have found that ketogenic diets may slightly increase the amount of fat you burn during rest, daily activity, and exercise, although more research is needed.

Ketogenic Diets and Metabolic Diseases

Ketogenic diets can improve many aspects of metabolic syndrome, a major risk factor for obesity, type 2 diabetes, and heart disease. Insulin also plays an important role in diabetes and metabolic disease. Ketogenic diets are extremely effective for lowering insulin levels, especially for people with type 2 diabetes or prediabetes.

One older study found that after only two weeks on a ketogenic diet, insulin sensitivity improved by 75%, and blood sugar dropped from 7.5 mmol/l to 6.2 mmol/l. A 16-week study also found a 16% reduction in blood sugar levels. Additionally, seven of the 21 participants were able to completely stop all diabetic medication.

Potential Drawbacks of Ketogenic Diets

Some experts have questioned the health benefits of the keto diet and called for more research. While it may help you lose weight, there may also be complications.

A ketogenic diet is high in saturated fat, which has been linked to an increased risk of heart disease. It may also lead to nutrient deficiencies, liver problems, kidney problems, constipation, fuzzy thinking, and mood swings.

Additionally, the keto diet can be hard to stick to in the long term, especially when dining out or gathering with family and friends. Furthermore, studies on the health effects of following the keto diet for long periods are lacking.

Before starting any new diet, remember to ask your doctor if it's a suitable option for you.

How do ketogenic diets promote weight loss?

Ketogenic diets promote weight loss in several ways:

• Higher protein intake: Ketogenic diets often lead to an increase in protein intake, which has many weight loss benefits.
• Gluconeogenesis: Ketogenic diets can cause the body to convert fat and protein into carbs for fuel. This process may burn many additional calories each day.
• Appetite suppression: Ketogenic diets help you feel full. This is supported by positive changes in hunger hormones, including leptin and ghrelin.
• Improved insulin sensitivity: Ketogenic diets can drastically improve insulin sensitivity, which can help improve fuel utilization and metabolism.
• Decreased fat storage: Ketogenic diets may reduce lipogenesis, the process of converting sugar into fat. This is because excess carbs are stored as fat. When there’s a minimal intake of carbs, fat is used for energy.
• Increased fat burning: Several studies have found that ketogenic diets may slightly increase the amount of fat you burn during rest, daily activity, and exercise, although more research is needed.

It's important to note that while ketogenic diets can be effective for weight loss, they may not be suitable or sustainable for everyone. Some people may find them difficult to stick to in the long term due to their restrictive nature. Additionally, there is a lack of long-term research on the health effects of following a ketogenic diet for extended periods.

A ketogenic diet and metabolic diseases

The ketogenic diet is a low-carb, high-fat diet that has been proven to help people lose weight and fight metabolic disease. It involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbs puts your body into a metabolic state called ketosis, where fat becomes the primary energy source.

Weight Loss and Metabolic Syndrome

Obesity and metabolic syndrome are global epidemics. Metabolic syndrome is a cluster of risk factors, including abdominal obesity, high triglycerides, blood pressure, and blood sugar, as well as low HDL ("good") cholesterol. A ketogenic diet has been shown to be effective in managing weight and the components of metabolic syndrome.

A study on 30 adults with metabolic disease found that those who followed a ketogenic diet for 10 weeks lost more weight and body fat and lowered their A1C levels compared to those on a standard American diet. Another study on 45 obese participants found that a very low-calorie ketogenic diet resulted in about 27 pounds of weight loss on average after two years, compared to less than 10 pounds in the low-calorie group.

Diabetes

There is conflicting evidence on the effects of a ketogenic diet on diabetes. Some studies suggest that a ketogenic diet can improve glucose homeostasis and reduce antidiabetic medications in type 2 diabetes patients. However, other studies indicate that a ketogenic diet can induce insulin resistance and glucose intolerance in rats.

Polycystic Ovary Syndrome (PCOS)

PCOS is a metabolic condition that increases the risk of insulin resistance, diabetes, and obesity in women. A small study found that a ketogenic diet may be positive for women with PCOS, but more long-term research is needed.

Heart Disease

The ketogenic diet can help improve risk factors for heart disease, such as body fat, HDL ("good") cholesterol levels, blood pressure, and blood sugar. However, there are concerns about the high saturated fat content of the diet, which may lead to an increase in "bad" LDL cholesterol, also linked to heart disease.

Hypertension

Most studies show positive effects of a ketogenic diet on hypertension. However, one study on spontaneously hypertensive rats found that the diet aggravated hypertension and impaired endothelium-dependent relaxation.

Vascular Function and Blood Flow

The effects of a ketogenic diet on vascular function and blood flow are inconclusive. Some studies suggest that it can enhance neurovascular function and regional cerebral blood flow, while others show no significant effect on carotid intima-media thickness and elastic properties of the carotid and aorta arteries.

Serum Lipids

The impact of a ketogenic diet on serum lipids is also inconclusive. Some studies show a decrease in fasting serum triglyceride, postprandial lipemia, and fasting serum insulin concentrations, while others show an increase in serum total and LDL cholesterol and triglyceride levels.

Cardiovascular Complications of Metabolic Diseases

The effects of a ketogenic diet on cardiovascular complications of metabolic diseases are mixed. It appears to be generally protective against obesity-related cardiovascular disease but remains controversial for diabetes and other metabolic disorder-related CVDs.

Safety Concerns

There are some safety concerns associated with a ketogenic diet, including potential adverse effects on heart functions, liver inflammation, and elevated lipid levels. However, the majority of studies have found the diet to be beneficial, and the safety concerns may be transient or reversible.

Factors Affecting Ketogenic Diet Responses

Genetic background, duration of therapy, food composition, quality, and sources of ketogenic diets can all influence the outcomes and should be considered when initiating this type of diet.

Impact on metabolic disease

The ketogenic diet has been found to improve metabolic and inflammatory markers, including lipids, HbA1c, high-sensitivity CRP, fasting insulin and glucose levels, and aid in weight management.

Obesity and metabolic syndrome

Obesity and metabolic syndrome are epidemics in the Western world. Obesity has nearly tripled since 1975, with worldwide rates of overweight and obesity in excess of 39% and 13% respectively. Metabolic syndrome is a systemic inflammatory state associated with a 5-fold increased risk of diabetes and a 2-fold risk of cardiovascular disease.

The five main components of metabolic syndrome – obesity, fasting blood sugar, high triglycerides, low HDL cholesterol, and hypertension – are all improved by carbohydrate restriction, suggesting that carbohydrate intolerance is a common thread.

Ketones – an alternative fuel source

Humans have metabolic flexibility with the capability to rely on alternative fuel sources for energy. Ketones – acetoacetate, beta-hydroxybutyrate, and acetone – are water-soluble molecules produced by the liver from fatty acids when blood glucose and liver glycogen stores are low. Ketogenesis, the production of ketones for fuel, is a normal, physiological process.

Through ketogenesis, fat-derived energy is generated in the liver and then supplied throughout the body to supply energy to the brain, renal cortex, heart, and skeletal muscles. Ketones can supply up to 60% of ATP required by the body; the remainder is derived from endogenous gluconeogenesis.

Origins of the ketogenic diet as a medical therapy

The ketogenic diet was originally introduced in 1920 as a way to manage epilepsy and minimise seizure activity. More recently, it has become known as a method for obesity treatment. Research has also provided evidence for the therapeutic potential of ketogenic diets in many pathological conditions, including diabetes, PCOS, acne, neurologic diseases (epilepsy, Alzheimer’s, CVA), cancer, and the amelioration of respiratory and cardiovascular disease risk factors.

Reduction of carbohydrates and nutritional ketosis

Reduction of carbohydrates to induce nutritional ketosis can result in significant improvements to blood lipid profiles, even in the setting of increased saturated fat intake. The main improvements in lipid biomarkers include a marked reduction in plasma triglyceride levels, significant positive effects on total cholesterol reduction, increased HDL cholesterol, and a shift in size and volume of LDL particles.

Glycemic control, insulin sensitivity, and diabetes

Nutritional ketosis can improve glycemic control and reduce medication usage. Several studies have demonstrated a correlation between carbohydrate intake and size and density of LDL particles, a relationship that appears even more robust in individuals with diabetes. Smaller and denser LDL particles are known to be directly associated with a significant increase in the risk of cardiovascular disease.

Hepatic steatosis (NAFLD)

NAFLD is the hepatic manifestation of metabolic syndrome, characterised by hepatic steatosis in the absence of other well-known forms of hepatic injury. A small, two-week clinical trial found that a carbohydrate-restricted diet led to a greater reduction in intra-hepatic triglyceride content than a calorie-restricted diet.

Long-term effects of a ketogenic diet in obese patients

A study of 83 obese patients found that a ketogenic diet significantly reduced the body weight and body mass index of the patients. Furthermore, it decreased the level of triglycerides, LDL cholesterol and blood glucose, and increased the level of HDL cholesterol. Administering a ketogenic diet for a relatively longer period of time did not produce any significant side effects in the patients.

Summary

The ketogenic diet has been found to improve metabolic and inflammatory markers, including lipids, HbA1c, high-sensitivity CRP, fasting insulin and glucose levels, and aid in weight management. It can also decrease the risk factors for various chronic diseases, including heart disease, and is currently being explored as an additional treatment for cancer.

Should you try a ketogenic diet?

The ketogenic diet is a high-fat, low-carb, and moderate-protein eating plan that has been advertised as a weight-loss wonder. However, it is actually a medical diet that comes with serious risks and should only be done under medical supervision.

The keto diet aims to force your body to use a different type of fuel. Instead of relying on sugar (glucose) from carbohydrates, the keto diet relies on ketone bodies – a type of fuel that the liver produces from stored fat. To reach a state of ketosis, you must deprive yourself of carbohydrates (less than 20-50 grams of carbs per day) and eat fat at every meal.

Who should try the keto diet?

The keto diet is used to help reduce the frequency of epileptic seizures in children. It can also be used as a short-term dietary change to jumpstart weight reduction.

Who shouldn't try the keto diet?

A ketogenic diet is not suitable for everyone. It may benefit people who are obese or have a higher chance of developing metabolic syndrome, but it is not recommended for people with disorders of fat metabolism, carnitine deficiency, or pyruvate kinase deficiency.

A ketogenic diet is associated with an increase in "bad" LDL cholesterol, which is linked to heart disease. It is also high in saturated fat, which may cause or worsen liver problems. Other potential risks include nutrient deficiency, kidney problems, constipation, and fuzzy thinking and mood swings.

The keto diet is an effective weight loss diet that is well-supported by evidence. It can help you lose fat, preserve muscle mass, and improve markers of disease. It is also very filling and usually does not require calorie counting.

The keto diet may be hard to stick to in the long term due to its restrictive nature. It can be challenging when dining out or gathering with family and friends, as a new way of eating must be adopted. Additionally, there is a lack of long-term studies on the health effects of the keto diet.

• Base most of your meals on low-carb veggies and high-fat meats, fish, or eggs.
• Monitor your ketone levels to ensure you are keeping carb levels down sufficiently to achieve ketosis.
• Make sure you're drinking enough water and getting proper amounts of electrolytes, like sodium, potassium, and magnesium.
• Be consistent. With any diet, consistency is the most important factor.

• MCT oil: Helps keto dieters add more fat to their diets and stay in ketosis.
• Exogenous ketones: Increase blood ketone levels and help you achieve ketosis more rapidly.
• Keto protein powders: Formulated to have a low-carb content.
• Keto electrolytes: Help prevent deficiency of common electrolytes like sodium, potassium, and magnesium.
• Digestive enzymes: Help break down fats and address digestive issues caused by the high-fat content of the keto diet.

• Your exact carb intake: Eating too many carbs will prevent you from staying in ketosis and diminish the potential benefits of the diet, including weight loss.
• Sleep: A lack of sleep can negatively impact weight loss outcomes and hunger hormones, causing increased appetite.
• Exercise: Combining the keto diet with a proper exercise regimen can enhance weight loss.
• Sustainability: The keto diet may be difficult to stick to in the long term due to its restrictive nature.
• Calorie counting: To lose weight, you need to burn more calories than you consume. Even if you are in a state of ketosis, consuming too many calories may lead to weight gain.

The ketogenic diet can provide amazing results if you stick to it. However, it may not be the best option for everyone. Before starting any new diet, remember to ask your doctor if it is a suitable option for you.

Frequently asked questions