The Atkins Diet, formally known as the Atkins Nutritional Approach, is a popular low-carbohydrate eating plan developed in the 1960s by cardiologist Robert C. Atkins. The purpose of the Atkins Diet is to change your eating habits to help you lose weight and keep it off. This diet has several phases for weight loss and maintenance, starting with a very low-carbohydrate eating plan. Like many diet plans, the Atkins Diet keeps changing. It now encourages eating more high-fiber vegetables and has included changes to meet vegetarian and vegan needs.
Core Principles of the Atkins Diet
The Atkins Diet posits that obesity and related health problems, such as type 2 diabetes and heart disease, are a result of the typical low-fat, high-carb American diet. The diet emphasizes that you don't need to avoid fatty cuts of meat or trim off excess fat. Instead, the Atkins Diet holds that eating too many carbs - especially sugar, white flour, and other refined carbs - leads to blood sugar imbalances, weight gain, and heart problems. To that end, the Atkins Diet limits carbs and encourages eating more protein and fat. The Atkins Diet doesn't require calorie counting or portion control, but you do need to track your carbs using a system called net carbs. Net carbs is the total carbohydrate content of an item minus its fiber content. For example, a half-cup (4 ounces) of raw broccoli has 2.3 grams of total carbs and 1.3 grams of fiber.
The Atkins Diet claims its approach to carbs will burn off your body's fat stores, control your blood sugar, and help you achieve optimal health. Once you're at your goal weight, the Atkins Diet also explains it will help you find your personal carbohydrate balance.
The Four Phases of the Atkins Diet
The Atkins Diet has four distinct phases, each with its own set of guidelines and goals.
Phase 1: Induction
In this strict phase, you cut out almost all carbohydrates from your diet. Instead of getting about half of your daily calories from carbohydrates, as recommended by most nutrition guidelines, you get only about 10%. In this phase, you eat protein, such as fish and shellfish, poultry, meat, eggs, and cheese, at every meal. You don't need to limit oils and fats. But you can't have most fruits, sugary baked goods, breads, pastas, grains, nuts, or alcohol. You drink at least eight glasses of water a day.
Read also: Understanding the Atkins Diet
Phase 2: Balancing
In this phase, you keep eating a minimum of 12 to 15 grams of net carbs as foundation vegetables. You also keep avoiding foods with added sugar. You can slowly add back in some carbs that are high in nutrients, such as more vegetables and berries, nuts, and seeds, as you keep losing weight.
Phase 3: Pre-maintenance
In this phase, you slowly keep increasing the range of foods you can eat, including fruits, starchy vegetables, and whole grains. You can add about 10 grams of carbs to your diet each week. But you must cut back if your weight loss stops.
Phase 4: Lifetime maintenance
You move into this phase when you reach your goal weight. The aim is to maintain this weight by eating as many healthy carbs as your body can tolerate without regaining weight.
Sample Meals and Snacks
Here are some examples of what you might eat on the Atkins Diet:
- Breakfast: Egg-filled avocado with prosciutto.
- Lunch:
- Dinner:
- Snacks: You typically can have two snacks a day. Snacks may include an Atkins Diet product, such as a chocolate shake or granola bar.
Effectiveness and Scientific Evidence
The Atkins Diet says that you can lose a large amount of weight in the first two weeks of phase 1 - but it also states that those aren't typical results. The Atkins Diet also notes that you may lose water weight at first. Most people can lose weight on almost any diet plan that restricts calories - at least in the short term. Over the long term, though, studies show that low-carb diets like the Atkins Diet are no more effective for weight loss than are standard weight-loss diets. Because carbs usually provide over half of calories consumed, the main reason for weight loss on the Atkins Diet is lower overall calorie intake from eating less carbs. Some studies suggest that there are other reasons for weight loss with the Atkins Diet. You may shed pounds because your food choices are limited. And you eat less since the extra protein and fat keep you feeling full longer.
Read also: Delicious Atkins Dinners
The Atkins Diet says that its eating plan can prevent or improve serious health conditions, such as metabolic syndrome, diabetes, high blood pressure, and heart disease. And most weight-loss diets - not just low-carb diets - may improve blood cholesterol or blood sugar levels, at least temporarily. One study showed that people who followed the Atkins Diet had improved triglycerides, suggesting better heart health.
Potential Risks and Side Effects
Some very low-carb diets also restrict carbs so much that they cause you not to have enough nutrients or fiber. This can cause such health problems as constipation, diarrhea, and nausea. It's also possible that restricting carbohydrates to less than 20 grams a day - the level recommended for phase 1 of the diet - can result in ketosis. Ketosis occurs when you don't have enough carbohydrates that are broken down into sugar (glucose) for energy, so your body breaks down stored fat. This causes ketones to build up in your body. In addition, the Atkins Diet isn't a good idea for everyone.
For example, the Atkins Diet recommends that you talk to your health care provider before starting the diet if you take diuretics, insulin, or oral diabetes medications. Also, people with severe kidney disease shouldn't follow the diet.
The Atkins Fat Fast
The fat fast is a technique brought by Dr. Atkins’ New Diet Revolution - used by people who are metabolically resistant and have trouble with their induction. It is important to stress that a fat fast should only be followed for a few days maximum as it does not provide sufficient protein and other nutrients. To be clear: You should not fat fast consistently.
What is a Fat Fast?
A fat fast involves eating between 1000 and 1200 calories a day, where between 80% and 90% of your calories come from fat. It is normally done for 2-4 days but is never recommended to go for more than 5 days. Hungry? You most likely will be at first, but once your body starts adapting to the way you are eating, you will notice a drop in your hunger. If you’re doing a fat fast, I recommend doing a 3 day fast. This normally drops about 5-8 pounds of body fat and water weight.
Read also: Atkins Diet for Vegetarians
Purpose of the Fat Fast
The fat fasting technique is essentially an accelerated version of the keto diet. Rapid weight loss. Breaking through weight loss plateaus. If you have been experiencing a weight loss stall for two weeks or longer, following a fat fast may be an effective strategy. Increasing ketone levels.
Potential Downsides
However, as with other highly restrictive weight loss approaches, the fat fast can come with a few downsides as well.
Side Effects
Along with the potential for rapid weight loss and ketosis, the fat fast can come with a few side effects. Fortunately, there are a few simple ways to remedy these symptoms, such as maintaining proper hydration, increasing electrolyte intake, and taking MCT oil. Other than the keto flu, the fat fasting technique can also cause rapid fluctuations in blood sugar, blood pressure, hormones, and weight.
What to Eat During a Fat Fast
There’s not all that much choice you have, as you have to keep the calories relatively low and the fat very high. Feel free to mix meat in there, but be careful about the amount of meat you actually eat.
Examples of foods to eat:
- Chicken, tuna, turkey, bacon, prosciutto, etc.
- ½ medium avocado mashed with 1 tbsp.
- 1 oz. Macadamia nut butter with 2 oz.
- 1 oz. chicken with 2 tbsp.
- 2 egg yolks with 1 tbsp.
- 2 oz.
By making the recipes in this meal plan, you’ll have plenty of extra servings that you can use to kick-start your regular ketogenic diet or extend your fat fast for another day or two. If you would rather keep your fat fast as easy as possible, then simply pick a couple suggestions from the list of suggestions above and eat between 1000 and 1200 calories of them during your fat fast. Just make sure you are getting 80- 90% of your calories coming from fat. If you’re unlike me and just love cream cheese, then you can snack on a full 8 oz. block of cream cheese for the day along with a cup of coffee with 2 1/2 tbsp.
Atkins Diet: Acceptable and Unacceptable Foods
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)
You should base your diet around these foods while on the Atkins diet:
- Meats: beef, pork, lamb, chicken, bacon, and others
- Fatty fish and seafood: salmon, trout, sardines, and mackerel
- Eggs: omega-3 enriched or pastured - most nutrient-dense (16)
- Low-carb vegetables: kale, spinach, broccoli, asparagus, and others
- Full-fat dairy: butter, cheese, cream, full-fat yogurt
- Nuts and seeds: almonds, macadamia nuts, walnuts, sunflower seeds
- Healthy fats: extra virgin olive oil, coconut oil, avocados, and avocado oil
- Whole grains: brown rice, oatmeal, bulgur, quinoa, teff
Build your meals around a high-fat protein source with plenty of vegetables, nuts, and some healthy fats, while only including small portions of complex carbs that fit within your individual daily carb goal.
Acceptable Beverages
Here are some drinks that are acceptable on the Atkins diet.
- Water: As always, water should be your go-to beverage.
- Coffee: Coffee is high in antioxidants and may offer health benefits.
- Green tea: Green tea is also high in antioxidants.
You can drink alcohol in small amounts while on the Atkins diet. Stick to dry wines with no added sugars and avoid high carb drinks like beer, try to stay away from mixed drinks like cocktails as they tend to have the most sugar among alcoholic beverages.
Plant-Based Atkins Diet
Following a plant-based Atkins diet requires extra planning. Since meals on the Atkins diet are based around high-fat sources of protein (typically from meat, fatty fish, and dairy), people eating a vegetarian or vegan diet need to substitute with alternatives to make sure they are meeting their nutrient needs. About 43% of what you eat should come from healthy plant-based fat sources such as avocado, nuts and seeds, olive oil, and coconut oil. About 31% of your food should be protein from plant-based sources like soy or beans.
Lacto-ovo-vegetarians can also eat eggs, cheese, butter, heavy cream, and other high-fat dairy foods.
Useful Tips for 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 this sample 3-week menu of Atkins-friendly meals.
- Shop wisely: Here is 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. Here is a guide to 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. One metabolite of the gut microbiota, known as tri-methylamine N-oxide (TMAO), is a predictor of incident cardiovascular disease events, like heart attack and stroke. In one study of several popular diets’ effects on TMAO, the Atkins diet was associated with a higher risk of cardiovascular disorders (as measured by levels of TMAO) when compared with a low fat (Ornish).
Atkins Diet: Is it the Same as Keto?
Atkins and keto are both low-carb diets that can promote weight loss, diabetes management, and heart health. The difference is the carb intake: Atkins allows you to increase carb consumption slowly over time, while keto asks you to keep low to allow for ketosis and fat burning.
Atkins and Belly Fat Loss
In one 2020 study on older adults living with obesity, researchers found that participants who followed a very low carb diet like Atkins did lose some belly fat. That said, more research is needed to understand if this is the case across other age groups and states of health.
Carbohydrate Intake on Atkins
The amount of carbs you eat in a day depends on the phase of the diet you’re in. You begin the diet with just 20 g of carbs daily for two weeks and slowly increase the amount as your diet progresses. That said, the amount of carbs you eat in a day while on the Atkins diet will depend on your carb tolerance and weight loss or weight maintenance goals.
Final Thoughts
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. That said, if you’re serious about the Atkins diet, consider buying or borrowing one of the Atkins books to learn more before getting started or print this article to use as a guide.
As always, consult a doctor or registered dietitian before starting a new weight-loss diet to make sure it’s right for your individual health needs.