The Atkins diet is a popular weight loss plan that focuses on restricting carbohydrates while emphasizing proteins and fats. It's similar to other ketogenic diets and aims to help you burn fat for fuel instead of sugar. Proponents of the Atkins diet say its high-fat, high-protein menu and focus on vegetables may help you feel satiated and more energetic. The goal of the eating plan is to resolve many of the health problems associated with a diet high in refined carbohydrates, such as white sugar and flour.
Understanding the Atkins Diet
The Atkins diet has evolved since its creation in 1972 by cardiologist Robert Atkins. There are now two main versions: Atkins 20 (the original diet, based on 20 grams of Net Carbs per day) and Atkins 40 (a less strict version, based on 40 grams of Net Carbs). The main features of the diet haven't changed: lose weight and improve health by eating a low-carbohydrate diet that consists of protein, vegetables, and healthy fats.
The Atkins Food Guide Pyramid
The Atkins diet uses a food guide pyramid to illustrate the principles of the diet. At the top of the pyramid are foods that you can eat a little of, but only after you have lost weight. These include whole grains such as barley, oats, and rice. Missing from the Atkins Food Pyramid are "white" foods, which are forbidden foods that you should avoid. These include white sugar, white rice, white bread, white potatoes, and pasta made with white flour.
Net Carbs
You don't have to count calories on the Atkins diet as long as you are reasonable with portion sizes. The only thing you have to calculate is carbohydrates. Specifically, you need to count Net Carbs, which are the total grams of carbohydrates minus grams of fiber.
The Four Phases of the Atkins Diet
The Atkins diet works in four phases:
Read also: Understanding the Atkins Diet
- Phase 1: Induction. This is the most restrictive part of the diet. You eliminate almost all carbohydrates during the first two weeks of the diet, consuming only 20 grams of Net Carbs daily. That means saying goodbye (for now) to most fruits, dairy, legumes, juices, whole grains, and starchy vegetables. The goal of phase 1 is to rev up your body's ability to burn fat. And because you lose the most weight during this phase, it is designed to motivate you to stick with the diet.
- Phase 2: Balancing. During phase 2, you slowly add some whole food carbohydrates back to your diet, such as berries, legumes, nuts, tomato juice, and yogurt. You can eat between 25 and 50 Net Carbs daily. Phase 2 lasts until you are about 10 pounds from your desired weight.
- Phase 3: Fine-tuning. During phase 3, you continue to add a variety of carbohydrates to your diet, including more fruits, starchy vegetables, and whole grains. You can eat 50 to 80 Net Carbs daily. Phase 3 lasts for at least a month after reaching your desired weight.
- Phase 4: Maintenance. Once you reach your ideal weight, you continue to eat a predominantly low-carbohydrate (80-100 Net Carbs per day) diet for life. By this time, you should have a good idea of how many carbohydrates you can eat to maintain your weight.
The Science Behind the Atkins Diet
The main idea behind the Atkins diet is to change your metabolism so that you burn fat for energy instead of glucose, a process called ketosis. When you eat foods high in carbohydrates, such as refined sugar, your body turns it into glucose. Your body can only store a certain amount of glucose. Extra glucose that your body cannot store is converted to fat. The theory goes that if you significantly cut back on the amount of carbohydrates you eat, your body will spend more time burning fat and you will lose weight.
Not only does the Atkins diet change your metabolism, studies show that eating more protein helps to curb appetite. Studies have shown that people who stick to a low-carbohydrate diet like Atkins can lose weight. A study in The Journal of the American Medical Association comparing diets found that women on the Atkins diet lost more weight and experienced more health benefits. After one year on the Atkins diet, people in the study lost an average of 10 pounds. They also had improved triglyceride levels and lower blood pressure. But experts say any diet that helps you lose weight will probably improve your cholesterol.
Since most studies on the Atkins diet last a year or less, researchers don't know if the health benefits from the diet are maintained and if the diet is safe for long-term use.
Potential Benefits and Risks
In comparison to a diet that restricts fat, some evidence suggests ketogenic diets, like Atkins, may show promise as treatments for diabetes and obesity, according to an article in The Journal of Nutrition. Research suggests they may support healthy blood glucose and insulin levels and may help with diseases linked with insulin resistance, such as cancer and neurodegenerative conditions.
However, there are also risks to consider before starting Atkins or other low-carb diets. Drastically reducing carbs in phase 1 may result in headaches, dizziness, weakness, fatigue, or constipation, as well as nutritional deficiencies. Your body may also enter a state of ketosis. This is when your body breaks down fat instead of carbs for fuel. Side effects of ketosis include nausea, headaches, mental fatigue, and bad breath.
Read also: Delicious Atkins Dinners
Foods to Enjoy on the Atkins Diet
Before you start your weight loss journey with Atkins, it’s important to stock up on the foods you’ll need to follow an effective, low carb diet. Once your refrigerator is full of low carb ingredients, cooking delicious and healthy meals will be easy.
Keto-Friendly Carbs
The main component of a keto diet is to lower your carb intake to 20-40 net grams per day to achieve ketosis. To ensure you’re still getting the vitamins, minerals, and fiber your body requires, it is important that the carbs you do eat come from nutrient-rich, non-starchy sources. Eating plenty of whole foods also helps you stay fuller longer and prevents sugar cravings.
- Low carb vegetables: Aim to eat 12-15g of net carbs from a variety of vegetables per day. The following are some keto friendly low carb veggies: asparagus, broccoli, Brussels sprouts, cabbage, cauliflower, celery, cucumber, green beans, kale, peppers (red and green), spinach, and zucchini.
- Low carb fruits: When it comes time to adding low carb fruits into your diet, reach for low glycemic varieties like blackberries, blueberries, coconut, lemons and limes, raspberries, strawberries, and tomatoes. Olives and avocados, which are also technically a fruit, are also a great source of healthy fat.
Keto-Friendly Protein
Protein should make up 20-30% of your diet. Eating the right balance of protein while on a low carb diet is important in protecting muscle mass and supplying the amino acids needed for additional pathways in the body.
- Meat, poultry, and eggs: Meat and poultry are excellent no-net-carb sources of protein and some of the most keto-friendly foods. Make sure to get your protein from a variety of different sources and aim for three 4-6 ounce cooked servings of protein each day in order to get adequate protein. Eggs are also packed with protein as well as vitamin A and antioxidants. Enjoy your eggs any style, especially with some foundation vegetables mixed in for a filling, balanced meal. Examples include: bacon, beef, eggs, ham, lamb, pork, poultry/fowl, veal, and venison. Remember that some processed meats, bacon, and ham are cured with sugar, which will add to the carb count. If possible, avoid cold cuts and other meats with added nitrates.
- Fish and shellfish: Fish and shellfish are rich in protein, Omega-3 fatty acids, and healthy fats as well as a great source of vitamins D and B2, calcium, and minerals like zinc, copper, iron, magnesium, and potassium. Aim for 4-6 ounce servings of cooked fish or shellfish a couple times a week, and try to avoid products that are higher in carbs like imitation crab. Examples include: clams, cod, crabmeat, flounder, halibut, herring, lobster, mackerel, mussels, oysters, salmon (wild), sardines, shrimp, sole, squid, tuna, and trout.
- Cheese and other dairy: Because cheese contains about 1 gram of carbs per ounce, try to consume no more than 4 ounces per day (an ounce is about the size of a 1-inch cube). We recommend choosing the full-fat varieties when possible. Examples include: bleu cheese, butter/ghee, cheddar cheese, cottage cheese, cream, cream cheese, feta, goat cheese, gouda, Greek yogurt (plain), mozzarella (whole milk), Parmesan, and Swiss.
Keto-Friendly Fats
Low carb keto diets replace your reduction of carbs with an increase in fat, typically accounting for at least 60% of your daily calories. Make sure to choose healthy fats from high-quality plant and animal sources, such as olive oil, avocado oil, and nuts, as well as cheese, eggs, meat, and fish, which are also protein sources.
- Oils and other healthy fats: While these oils are free of carbs, the recommended daily intake for added fats is 2-4 tablespoons. Steer clear of unhealthy fats like partially hydrogenated oils. When cooking with the following healthy options, avoid heating oils above their smoke point. Examples include: avocado oil, coconut butter, coconut oil, mayonnaise (with no added sugar), MCT oil, olive oil, safflower oil, sesame oil, and walnut oil.
- Nuts and seeds: Low in carbs and high in fat, nuts and seeds are a great source of protein and make for a healthy snack or salad topping. Seeds are also a great source of fiber. Try to avoid nuts coated in extra sugar or “flavored” nuts, as the flavoring typically adds extra carbs. Consume almonds, cashews, pine nuts, and pistachios in moderation, as they have a higher carb count than the nuts and seeds listed below. Examples include: Brazil nuts, chia seeds, flaxseeds, hemp seeds, hazelnuts, macadamia nuts, pecans, pumpkin seeds, sunflower seeds, sesame seeds, and walnuts.
Keto-Friendly Beverages
Low carb diets like keto have a diuretic effect, so make sure to drink a minimum of 6 to 8 glasses of water daily-especially during the induction phase- to support your metabolism and regular body functions. Not consuming enough water can lead to constipation, dizziness, and cravings. Also make sure to add extra salt to your diet in order to make sure you’re getting enough electrolytes. Try sipping on full-sodium broth or adding a little extra salt to your food. Zero-calorie seltzers and club soda, up to two cups of decaffeinated or regular coffee and tea, herbal tea (without added barley or fruit sugar added), and unsweetened soy and almond milks, or any of these are also permitted.
Read also: Atkins Diet for Vegetarians
Seasoning
Add flavor to any meal with Atkins-approved seasonings such as parsley and chives.
Foods to Avoid or Limit
Individuals on the Atkins diet are told to avoid, or limit, the following foods:
- Sugar: Found in soft drinks, fruit juices, cakes, candy, ice cream, and similar products.
- Refined grains: White bread, white rice, white pasta.
- "Diet" and "low fat" foods: Are sometimes very high in sugar.
- High carb fruits: Bananas, apples, oranges, pears, grapes (induction only).
- Starchy vegetables: Potatoes, sweet potatoes (induction only).
- Legumes: Lentils, beans, chickpeas, etc. (induction only).
Sample Meal Plan (Phase 1)
It’s helpful to familiarize yourself with the Atkins diet’s list of phase 1 acceptable foods before you get started. Don’t starve yourself. Aim to eat every three to four hours throughout the day. Drink plenty of water, too - Mayo Clinic recommends at least eight glasses a day.
Here are a few ideas for Atkins diet recipes and foods to try in phase 1. For your meats, avoid processed meat, including bacon and ham that have been cured with sugar, and cold cuts and other meats with nitrates and other preservatives.
- Meal 1: Breakfast
- Spinach and cheese omelet topped with salsa and sliced avocado
- Lean strips of steak sautéed with allowed vegetables, such as sliced onion and bell peppers
- Smoked salmon with cream cheese and cucumber
- Two eggs with bacon and 1/2 cup of allowed vegetables
- Loaded veggie omelet cooked with allowed vegetables
- Meal 2: Lunch
- Salad with mixed greens topped with diced raw vegetables and grilled chicken
- Tuna salad spooned into fresh avocado halves
- Atkins-brand frozen entrée, such as Italian sausage primavera
- Chicken or turkey meatballs served over spaghetti squash
- Lean beef stir-fry with broccoli, bok choy, and onion
- Meal 3: Dinner
- Grilled fish served with steamed vegetables and a salad
- Ground beef burger with a lettuce “bun” and 1/2 cup of allowed vegetables
- Broiled pork chop with mashed cooked cauliflower mixed with cheese
- Grilled chicken and veggie kabobs
- Ground turkey taco salad with allowed veggies and 1 ounce shredded cheddar cheese
Eat one or two snacks between meals, and pair any higher-carb foods with a source of protein or fat. Examples of pairings include raw celery sticks with low-carb salad dressing, cherry tomatoes with your favorite allowed cheese, and cucumber slices with cream cheese. Remember to track your net carbs throughout the day so you stay within the limit. Finally, season your meals with salt, pepper, herbs, or spices, but avoid condiments with a high-carb content, such as ketchup or salad dressing containing added sugars.
Atkins Diet vs. Keto
The Atkins diet and the ketogenic (keto) diet are similar. Both focus on eating fat while limiting carbs. On the keto diet, fat can make up 90% of your calories each day. On Atkins 20, it's up to 70%. Researchers aren't clear whether the keto diet is safe or will help you keep weight off in the long term. Doctors mostly suggest it to lessen the number of seizures in kids with epilepsy.
Tips for Success on the Atkins Diet
The following tips and resources can help you follow the Atkins diet whether you’re eating at home or at a restaurant:
- Plan a weekly menu: Follow a sample menu of Atkins-friendly meals.
- Shop wisely: Use a suggested shopping list. Eating organic is not necessary but always try to choose the least processed option that fits your budget.
- Include snacks: Make a list of low-carb snacks you can turn to when you get hungry between meals.
- Eat out with caution: Ask for extra vegetables instead of bread, potatoes, or rice; order a meal based on fatty meat or fatty fish; Get some extra sauce, butter, or olive oil with your meal. Familiarize yourself with common Atkins substitutions you can make at various types of restaurants.
Potential Side Effects and Risks
Following the Atkins diet requires you to restrict certain nutrients that are important for your body. So while you may lose weight and experience other favorable metabolic changes, the Atkins diet can also result in the following side effects, particularly in the early phase of the diet:
- Headache
- Dizziness
- Fatigue
- Weakness
- Constipation
- Low blood sugar
- Kidney problems
- Electrolyte imbalance
Restricting carbohydrates on the Atkins diet also puts you at risk of not getting enough fiber, which helps protect against heart disease and certain types of cancer, helps regulate appetite, and supports gut motility and healthy gut microbiota. And, as mentioned earlier, the high saturated fat content of the Atkins diet may raise LDL (bad) cholesterol in some individuals. This may put you at increased risk of heart disease, though the research on this is conflicting.
Some research also suggests high fat diets, like the Atkins diet, influence the gut microbiome. Certain changes in the gut microbiome may be associated with an increased risk of cardiovascular disease.
Is the Atkins Diet Right for You?
The Atkins diet is not for everyone and may pose some risks - both short term and long term. The long-term risks include the possibility of changes in your gut microbiome as well as increased LDL “bad” cholesterol. Make sure to consult your doctor before beginning any kind of new diet.
The Atkins diet can be an effective way to lose weight, but it’s not for everyone. It may not always be easy to access fresh produce or high-quality meat, and relying heavily on these foods may prove quite expensive for many people. Additionally, restrictive diets have been shown to increase the likelihood of some individuals developing disordered eating habits.
People with high cholesterol or an increased risk of heart disease should monitor their cholesterol for unfavorable changes while on the Atkins diet. Those with diabetes should consult their doctor before beginning the Atkins diet. Additionally, individuals with kidney disease and people who are pregnant should not follow the Atkins diet.