The Atkins Diet: Everything You Need to Know

The Atkins diet is a low carb diet, usually recommended for weight loss.

Proponents of this diet claim that you can lose weight while eating as much protein and fat as you want if you avoid foods high in carbs.

Since the early 2000s, numerous studies have shown that low carb diets — without the need for calorie counting —are effective for weight loss and can lead to various health improvements (1Trusted Source, 2Trusted Source).

The Atkins diet was originally promoted by Dr. Robert C. Atkins, who wrote a best-selling book about it in 1972. Since then, people worldwide have used the Atkins diet, and many other books have been written about it.

The diet was initially considered unhealthy, mostly due to its high saturated fat content. Today, saturated fat’s effect on health and heart disease, in particular, is a topic of debate among researchers.

The saturated fat debate

Many studies show that eating saturated fat can raise LDL (bad) cholesterol, which is a risk factor for cardiovascular disease (3Trusted Source, 4Trusted Source).

A recent review that the American Heart Association conducted on saturated fat’s impact on heart disease concluded that replacing saturated fat with polyunsaturated fat can help lower cardiovascular disease by about 30 percent (3Trusted Source).

Some reviews also suggest that replacing saturated fat in your diet with polyunsaturated fats reduces the risk of cardiovascular events, like heart attacks and strokes (5Trusted Source, 6Trusted Source).

However, other reviews of the literature show no association between lowering saturated fat intake and reduced risk of developing or dying from cardiovascular disease (5Trusted Source, 6Trusted Source, 7Trusted Source, 8Trusted Source).

Furthermore, some experts believe that not all saturated fats have the same effects on heart disease risk (9). Others contend that overall diet is more important than singling out individual nutrients.

When compared with other diets, some studies suggest the Atkins and other low carb diets may lead to more weight loss and greater improvements in blood sugar, HDL (good) cholesterol, triglycerides, and other health markers than low fat diets. (10Trusted Source, 11Trusted Source).

Whether or not low carb, high fat (LCHF) diets like the Atkins diet raise LDL (bad) cholesterol appears to be on an individual basis.

In one study of 30 young individuals who were at average weight, following an LCHF diet for 3 weeks significantly increased LDL (bad) cholesterol, along with total cholesterol and HDL (good) cholesterol compared with the control group (12Trusted Source).

However, there was a wide variance in individual LDL responses to the diet. The individual increases in LDL (bad) cholesterol varied between 5 and 107 percent.

Another smaller 2021 study of healthy women between 18 and 30 years old with average weight, looked at the effect of an LCHF ketogenic diet on LDL (bad) cholesterol. Eating a strict LCHF diet rich in saturated fats for 4 weeks significantly increased LDL (bad) cholesterol in all study participants compared with a control diet (13Trusted Source).

This suggests that if you do try an LCHF diet like Atkins, you should monitor your cholesterol levels to gauge your body’s response.

One reason low carb diets can result in weight loss is that a reduction in carbs and increased protein intake may lead to reduced appetite, helping you eat fewer calories without having to think about it (14Trusted Source, 15Trusted Source).

The Atkins diet is a 4-phase plan

Here’s a brief summary of how to follow the Atkins diet. It’s always a good idea to consult your registered dietitian or physician before starting a new weight-loss diet plan.

The Atkins diet is split into 4 different phases:

• Phase 1 (induction): Under 20 grams of carbs per day for 2 weeks. Eat high-fat, high-protein, with low carb vegetables like leafy greens. This kick-starts the weight loss.
• Phase 2 (balancing): Slowly add more nuts, low-carb vegetables, and small amounts of fruit back to your diet.
• Phase 3 (fine-tuning): When you’re very close to your goal weight, add more carbs to your diet until weight loss slows down.
• Phase 4 (maintenance): Here you can eat as many healthy carbs as your body can tolerate without regaining weight.

However, all these phases may not be necessary.

Some people choose to skip the induction phase altogether and include plenty of vegetables and fruit from the start. This approach can be very effective and can help ensure you are getting enough nutrients and fiber as well.

Others prefer to stay in the induction phase indefinitely. This is also known as a very low carb ketogenic diet (keto).

Foods to 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
• grains: wheat, spelt, rye, barley, rice
• “diet” and “low fat” foods: are sometimes very high in sugar
• high carb vegetables: carrots, turnips, etc. (induction only)
• high carb fruits: bananas, apples, oranges, pears, grapes (induction only)
• starches: potatoes, sweet potatoes (induction only)
• legumes: lentils, beans, chickpeas, etc. (induction only)

Foods to eat

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 
• 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

Build your meals around a high fat protein source with plenty of vegetables, nuts, and some healthy fats.

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.

What about vegetarians?

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.

You can use soy-based foods for protein and eat plenty of nuts and seeds. Olive oil and coconut oil are excellent plant-based fat sources.

Lacto-ovo-vegetarians can also eat eggs, cheese, butter, heavy cream, and other high fat dairy foods.

A sample Atkins menu for 1 week

This is a sample menu for one week on the Atkins diet.

It’s suitable for the induction phase, but you should add more higher-carb vegetables and some fruits as you move on to the other phases.

Monday

• breakfast: eggs and vegetables, fried in coconut oil
• lunch: chicken salad with olive oil and a handful of nuts
• dinner: steak and veggies

Tuesday

• breakfast: bacon and eggs
• lunch: leftover chicken and veggies from the night before
• dinner: bunless cheeseburger with vegetables and butter.

Wednesday

• breakfast: omelet with veggies, fried in butter
• lunch: shrimp salad with some olive oil
• dinner: ground-beef stir fry with veggies

Thursday

• breakfast: eggs and veggies, fried in coconut oil
• lunch: leftover stir fry from dinner the night before
• dinner: salmon with butter and vegetables

Friday

• breakfast: bacon and eggs
• lunch: chicken salad with olive oil and a handful of nuts
• dinner: meatballs with vegetables

Saturday

• breakfast: omelet with various vegetables, fried in butter
• lunch: leftover meatballs from the night before
• dinner: pork chops with vegetables

Sunday

• breakfast: bacon and eggs
• lunch: leftover pork chops from the night before
• dinner: grilled chicken wings with salsa and veggies

Make sure to include a variety of different vegetables in your diet.

Nutritious lower-carb snacks

Many people feel that their appetite goes down on the Atkins diet. Some report feeling more than satisfied with three meals per day (sometimes only two).

However, if you feel hungry between meals, here are a few quick healthy snacks:

• leftovers
• a hard-boiled egg or two
• a few pieces of cheese
• a piece of meat
• a handful of nuts
• some Greek yogurt options
• berries and whipped cream
• baby carrots (careful during induction)
• fruits (after induction)

How to follow the Atkins diet when eating out

While it’s not always the easiest to follow the Atkins diet at many restaurants, it can be done. Some tips that may help include:

1. Ask for extra vegetables instead of bread, potatoes, or rice.
2. Order a meal based on fatty meat or fatty fish.
3. Get some extra sauce, butter, or olive oil with your meal.

A simple shopping list

Eating organic is not necessary but always try to choose the least processed option that fits your budget.

• meats: Beef, chicken, lamb, pork, bacon.
• fatty fish: Salmon, trout, etc.
• shrimp and shellfish.
• eggs.
• dairy: Greek yogurt, heavy cream, butter, cheese.
• vegetables: Spinach, kale, lettuce, tomatoes, broccoli, cauliflower, asparagus, onions, etc.
• berries: blueberries, strawberries, etc.
• nuts: almonds, macadamia nuts, walnuts, hazelnuts, etc.
• seeds: Sunflower seeds, pumpkin seeds, etc.
• fruits: Apples, pears, oranges.
• coconut oil
• olives
• extra virgin olive oil
• dark chocolate
• avocados
• Condiments: sea salt, pepper, turmeric, cinnamon, garlic, parsley, etc.

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 (17Trusted Source, 18Trusted Source):

• headache
• dizziness
• fatigue
• weakness
• constipation
• low blood sugar
• kidney problems
• electrolyte imbalance

Restricting carbohydrates on the Atkins diet also puts you at risk of insufficient fiber intake. Fiber is protective against heart disease and certain types of cancer, helps regulate appetite, and supports gut motility and healthy gut microbiota (16Trusted Source).

A large portion of the fiber we eat comes from whole grains and whole grain products, like breads and pastas. These foods are restricted on the Atkins diet.

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) diet (19Trusted Source).

The bottom line

If you’re serious about the Atkins diet, consider buying or borrowing one of the Atkins books to learn more before getting started.

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 (20Trusted Source).

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.

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.