Intermittent fasting is a popular way of eating that can help you lose weight and improve your health. It involves alternating periods of eating and fasting, which can change how your body uses energy and hormones. In this article, we will explain how intermittent fasting works for weight loss, what are the benefits and risks, and how to start it.
How does intermittent fasting work for weight loss?
Intermittent fasting works for weight loss by creating a calorie deficit and boosting your metabolism. A calorie deficit means that you burn more calories than you consume, which leads to weight loss. A boosted metabolism means that you increase the rate at which your body burns calories, which also leads to weight loss.
Intermittent fasting creates a calorie deficit by limiting the time and amount of food you eat. Depending on the method you choose, you may fast for 16 to 24 hours per day or for two days per week. During the fasting periods, you either eat nothing or very little (usually less than 500 calories). During the eating periods, you can eat normally, without counting calories or restricting food groups. By doing this, you reduce your overall calorie intake and lose weight.
Intermittent fasting boosts your metabolism by changing how your body uses energy and hormones. When you eat, your body breaks down food into glucose (sugar), which is then used for fuel or stored as glycogen in your liver and muscles. When you fast, your body depletes its glycogen stores and switches to burning fat for energy. This process is called ketosis.
Ketosis has several benefits for weight loss. First, it increases the production of ketones, which are molecules that suppress appetite and hunger hormones, such as ghrelin. This makes you feel less hungry and more satisfied during fasting periods. Second, it increases the levels of human growth hormone (HGH), which is a hormone that promotes muscle growth and fat burning. This helps you preserve muscle mass and lose fat mass during fasting periods. Third, it lowers the levels of insulin, which is a hormone that regulates blood sugar levels and promotes fat storage. This helps you access stored fat more easily and prevent fat accumulation during eating periods.
What are the benefits of intermittent fasting for weight loss?
Intermittent fasting can have various benefits for weight loss, such as:
Faster and easier weight loss: Intermittent fasting can help you lose weight faster and easier than other diets, because it creates a larger calorie deficit and boosts your metabolism . Studies have shown that intermittent fasting can be as effective as calorie restriction for weight loss , but with less effort and hunger.
Improved body composition: Intermittent fasting can help you improve your body composition by reducing body fat percentage and increasing lean muscle mass . This can make you look slimmer, fitter, and healthier.
Reduced risk of obesity-related diseases: Intermittent fasting can help you reduce the risk of obesity-related diseases, such as type 2 diabetes, heart disease, stroke, and cancer . This is because intermittent fasting can lower blood sugar levels, blood pressure, cholesterol levels, inflammation levels, and oxidative stress .
Enhanced mental health: Intermittent fasting can help you enhance your mental health by improving mood, cognition, memory, and brain function . This is because intermittent fasting can increase the production of brain-derived neurotrophic factor (BDNF), which is a protein that supports brain growth and repair.
What are the risks of intermittent fasting for weight loss?
Intermittent fasting is not suitable for everyone and may have some negative effects on some people, such as:
Hunger: Intermittent fasting can cause hunger pangs, cravings, and irritability, especially in the beginning. This can make it hard to stick to the plan and may affect your mood and productivity.
Fatigue: Intermittent fasting can lower your energy levels and make you feel tired, weak, and dizzy. This can impair your physical and mental performance and increase the risk of accidents and injuries.
Muscle loss: Intermittent fasting can cause muscle loss, especially if you fast for too long or too often. This can reduce your strength,
Headaches: Intermittent fasting can trigger headaches, especially if you are prone to migraines or have low blood sugar levels. This can affect your concentration and quality of life.
Nutrient deficiencies: Intermittent fasting can make it harder to get enough vitamins, minerals, and other nutrients. This can lead to deficiencies and health problems, such as anemia, osteoporosis, and hair loss.
Who should not try intermittent fasting for weight loss?
Intermittent fasting is not recommended for people who have certain medical conditions or special needs. These include:
Pregnant or breastfeeding women: Intermittent fasting can affect the amount and quality of breast milk and may harm the growth and development of the baby.
Children and adolescents: Intermittent fasting can interfere with the growth and development of children and teenagers and may cause eating disorders.
People with diabetes: Intermittent fasting can cause low or high blood sugar in people with diabetes. This can be dangerous and require medical attention.
People with eating disorders: Intermittent fasting can trigger or worsen eating disorders, such as anorexia, bulimia, or binge eating. This can have serious consequences for physical and mental health.
People with kidney stones: Intermittent fasting can increase the risk of kidney stones by increasing the concentration of urine and reducing the intake of fluids.
People with gout: Intermittent fasting can increase the levels of uric acid in the blood, which can cause gout attacks or worsen existing gout.
People with medication: Intermittent fasting can affect the absorption and effectiveness of some medications, such as blood thinners, anti-diabetic drugs, or anti-seizure drugs. This can cause adverse reactions or complications.
How to start intermittent fasting for weight loss?
If you want to try intermittent fasting for weight loss, you should talk to your doctor first to make sure it is safe and suitable for you. You should also follow some tips to make it easier and more effective:
Choose a method that fits your lifestyle and preferences. You can start with a shorter or less frequent fasting period and gradually increase it as you get used to it.
Drink plenty of water during your fasting period to stay hydrated and prevent dehydration. You can also drink other drinks that have no calories, such as black coffee, green tea, or herbal tea.
Eat balanced and nutritious meals during your eating period to get enough calories, protein, fiber, healthy fats, vitamins, minerals, and antioxidants. Avoid processed foods, added sugars, refined grains, trans fats, and alcohol.
Exercise regularly to boost your metabolism, burn fat, build muscle, and improve your health. However, avoid exercising too hard or too long during your fasting period as this may cause fatigue or muscle loss.
Listen to your body and adjust accordingly. If you feel unwell or experience any negative symptoms during intermittent fasting for weight loss, stop or change your plan. You may need to shorten your fasting period, increase your calorie intake, or take a break from fasting.
Intermittent fasting is a way of eating that can help you lose weight and improve your health. However, it also has some potential risks and is not suitable for everyone. If you want to try intermittent fasting for weight loss, you should talk to your doctor first and follow some tips to make it easier and more effective. Remember that intermittent fasting is not a magic solution for weight loss or health improvement. It is only one tool that you can use along with a healthy diet and lifestyle.
Dr. Karuturi Subrahmanyam, MD, FRCP (London), FACP (USA)
Internal Medicine Specialist
Phone : 85000 23456