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Atkins Diet: How It Works, Health Benefits, Plus Precautions
March 24, 2023
The Atkins diet — a popular low-carb diet that’s high in fats and proteins but low in carbohydrates — has been around for more than 40 years. Various books written about the Atkins diet are some of the best-selling in the diet category, with more than 45 million sold worldwide since its original publication in 1972.
The Atkins diet was created by an American cardiologist named Dr. Robert Atkins, a physician and nutritionist who developed his diet in the 1970s after researching potential benefits of reducing carb intake. He was specifically inspired by research conducted in the 1950s on the effects of low-carb diets, along with papers published on the same topic in the Journal of the American Medical Association.
What do you eat on the Atkins diet? Because it’s a low-carb diet, things like sugar, fruit, grains and many processed foods are avoided on the Atkins diet. Dr. Atkins believed that, instead, eating a low-carb diet that focuses on foods low-carb foods like meat, veggies, cheese and butter could help many struggling with weight gain quickly shed extra fat.
Below you’ll learn what the Atkins diet is, how it works, the different phases of the diet, what to eat in each phase and also some alternatives to consider based on potential dangers involved.
What Is the Atkins Diet?
The definition of the Atkins diet is “a diet high in protein and fat and low in carbohydrates, prescribed for weight loss.” Low-carb diets, including Atkins, have been used for several decades to help people lose excess weight and potentially improve certain health conditions.
The Atkins diet became popular in the U.S. and Europe during the 1990s and 2000s. However, in recent years sales of Atkins products and books have declined steadily. Packaged food products like bars and shakes have earned a reputation for being mostly unhealthy options, not to mention lacking taste. In 2005, the Atkins company filed for bankruptcy, although many dieters still refer to Atkins’ ideas and advice when attempting to lose weight fast .
While there’s evidence it leads to weight loss, is the Atkins diet healthy? Diets tend to affect people differently — for example, women versus men. While they’re not a good fit for everybody, low-carb diets like the Atkins diet have been linked to not only weight loss , but also certain other health benefits, too. These include:
- Reduced hunger or cravings (especially for sweets)
- Better control over insulin and blood sugar (glucose) spikes. This can be especially beneficial for prediabetics or diabetics, although low-carb diets aren’t the only way to reduce diabetes risk factors.
- Enhanced cognitive performance, including less brain fog or dips in energy
- In some cases, lower risk for heart disease factors
- Potentially reduced risk for certain types of cancer
How Does It Work?
There are several different types of the Atkins diet based on your individual goals, starting/current weight and willingness to eat only very low-carb foods. Some variations of the Atkins diet cut carbs more drastically than others. Generally speaking, the lower-carb the diet is, the likelier it is to result in very rapid weight loss (especially in obese individuals).
During the initial phases of the Atkins diet, carbs are kept to about 30–50 net grams (the amount of carbs left when fiber grams are subtracted). This is on par with the keto diet and considered to be “ very low carb ” according to most health authorities, while phases that include about 100 to 130 grams of carbs/day are considered “low carb” or moderate in carbs. As a point of reference, the Institute of Medicine proposes Americans obtain 45 percent to 65 percent of calories from carbohydrates, which is usually over 250 grams/day.
The Atkins diet works by boosting the body’s fat-burning abilities through consumption of only low-carb foods , along with an elimination of foods high in carbs/sugar. What is it about cutting carbs that causes fat loss? A heavy reduction, or in some cases almost an entire elimination, of glucose from carbohydrate foods causes the body to burn fat for energy instead.
Our bodies normally run on glucose for fuel, but fat and protein are used as backup sources when glucose is no longer available. We cannot make glucose ourselves and only store about 24 hours worth within our muscles and livers, so fat-burning and weight loss on Atkins can start to happen pretty quickly.
Glucose, or other types of sugar/carb molecules that can be turned into glucose once eaten, are found in all carbohydrate foods. This is exactly the reason grains and fruits, among other carbs, are off limits on the Atkins diet.
What can you eat on an Atkins diet? No-carb foods and low-carb foods that tend to be very popular among Atkins dieters include high protein foods , non-starchy veggies like leafy greens, oils and cheeses. The Atkins diet (as well as other variations of low-carb diets) reduces most sources of glucose. These include grains, legumes, starchy vegetables, fruits, and sugars or sweeteners of all kinds. Even even nuts, seeds and vegetables have some carbs, although amounts differ depending on the exact kind.
The Atkins diet is categorized into different levels and usually four phases, where you choose which foods to eat and avoid based on your current weight versus your target weight:
Phase 1 is the “Induction Phase,” which is described as the strictest carb-restrictive phase. You aren’t supposed to eat more than 20 grams of carbs per day for two weeks.
In other words, you eliminate almost all carbs from your diet (by consuming mostly no-carb foods like meat and fats) in order to switch your metabolism from depending on carbs/glucose for energy to stored body fat.
Phase 2 is the “Balancing Phase” (also called “Ongoing Weight Loss Phase”). You increase intake of carbs by around five grams daily for one to two weeks. The goal is to determine the maximum carbs your body can tolerate without causing you to regain weight or stop losing weight.
Most settle for between 25–30 grams of net carbs daily during this phase, coming from foods such as non-starchy veggies, seeds, nuts, lower-carb fruits and starchy veggies.
Phase 3 is the “Pre-Maintenance Phase.” You gradually start to eat more whole grains, starchy veggies and fruits. You do this slowly adding about 10 grams of net carbs to your diet weekly to monitor weight regain.
4. Lifetime Maintenance
Phase 4 is the final “Lifetime Maintenance Phase,” which you intend to basically continue forever. You reach this phase once you’ve achieved your target weight and are able to eat a variety of foods without regaining weight.
At this point, you should have a solid understanding of how many carbs daily your body can handle without gaining weight. You use this information to sustain a normal eating pattern complete with healthy carbs, veggies, fruits, fats, oils, meats, etc. You may also consider a carb cycling plan for this phase.
Phases 3 and 4 of the Atkins diet allow for more high-carb foods than Phases 1 and 2. During the later phases you can add the following whole foods:
- Fruits like citrus, apples, bananas, grapes, mangoes, papaya, pineapple and other starchy fruits
- Beverages like club soda, coffee and tea
- Legumes, such as red beans, string beans, black beans, horse beans and lima beans, among others
- All starchy veggies, such as squashes, carrots, beetroot, corn on the cob, and sweet and white potatoes
- You can also experiment with slowly adding grains back to your diet, though it’s recommended to add these in moderation if you’re prone to weight gain, sticking to mostly gluten-free, ancient grains
Foods to Eat
- Pastured eggs from chicken, turkey, etc.
- Fish and seafood (consume wild-caught fish and avoid shellfish, such as shrimp) — good choices are salmon, haddock or trout
- Organic and grass-fed beef pork, turkey and chicken
- Non-starchy veggies, such as spinach, cauliflower, Brussels sprouts, green beans, cabbage, canned cucumber, tomatoes, jalapeño peppers, broccoli, zucchini, bell peppers, lettuce and asparagus
- In phase 2, other veggies that have more carbs are added, such as tomatoes, zucchini, eggplant, squash, peppers, carrots, etc.
- Organic or unrefined coconut oil, grapeseed, walnut and olive oil
- Hard cheese, butter, sour cream and heavy cream (consume grass-fed and organic whenever possible, ideally made from raw milk) — approved cheese products include blue cheese, cheddar cheese, goat, feta, Swiss, parmesan and American cheese
- Herbs and spices like curry powder, cinnamon, thyme, cayenne pepper, cumin, paprika, chili powder, five-spice powder, dijon mustard, parsley, oregano, basil, tarragon, black pepper and garlic (whole or ground)
Foods to Avoid
- All grains (including wheat, barley, oats, rice and other whole grains), including all foods made with grain flour, such as bread, cakes, biscuits, chips, cereal, muffins, pasta, etc.
- Sugar and foods that contain artificial sweeteners or added sweeteners (honey, cane sugar, coconut sugar, etc.)
- Most fruits and fruit juices (lime or lemons are OK)
- Most premade condiments, sauces or packet mixes, which tend to be high in sugar
- Starchy veggies, such as carrots, potatoes, butternut/winter squash and parsnips
- Most dairy products that contain milk, yogurt, ricotta or cottage cheese. Higher-fat, low-carb cheeses are allowed because they have very little carbs.
- Alcohol, soda and other sweetened drinks
- Diet foods that have reduced fat and artificial ingredients. To make up for lost fat, these products are usually made with some sort of extra thickeners, carbs or sweeteners.
- Food made with hardened or hydrogenated oils, which include most junk foods or fast/fried foods
Does Atkins work? In terms of Atkins results, studies indicate that while low-carb diets have certainly been shown to help promote weight loss, especially in the first six to 12 months, and in some cases provide other health benefits, too.
However, overall, there is only weak evidence supporting Atkins’ effectiveness as a sustainable, long-term diet plan to lose weight. Ultimately, results from Atkins really depend on a person’s willingness to stick with the diet. Some people are better suited for low-carb diets than others.
Based on research focusing on low-carb diets, here are what studies tell us are some of the benefits that the Atkins diet can offer:
1. Leads to Weight Loss
Unlike many weight loss diets that involve counting calories and strict portion control, the Atkins diet focuses more on counting carbs (specifically net carbs, which takes into account how much fiber a food has). Research suggests that for those who lose weight on the diet, results are likely due to consuming less calories overall, possibly entering into ketosis , and feeling satisfied due to adequate protein, fat and fiber intake when followed properly.
A study done at Tulane University School of Public Health involving 148 subjects split between a low-fat diet group and a low-carb diet group found that even though the low-carb diet group ate higher amounts of dietary fat (participants were told to avoid trans fats and emphasize monounsaturated fats, polyunsaturated fats and saturated fats), the low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Both groups ate lots of vegetables, but the low-carb group included more healthy fats, such as olive oil, avocado, nuts, seeds and their butters, along with some dairy.
Consuming too many carbs (especially from refined sugar) is believed to be directly associated with fat gain, obesity, diabetes risk, cardiovascular diseases and other metabolically related medical conditions. The Atkins diet recommends that at least two-thirds of daily calories come from foods that are low in sugar/carbs but high in protein and fat, such as oils, meats and cheeses. Vegetables are also consumed with most meals, which provide volume, fiber and nutrients with little carbs.
2. May Help Prevent or Treat Diabetes
The Atkins diet replaces things like processed, high-carb/sugar foods that are prone to causing blood sugar swings, insulin resistance and weight gain — all causes of diabetes — with healthy fats and lean proteins (particularly from animal proteins, which are no-carb foods). As described above, removing foods like fruits, starchy veggies, pasta and bread from your diet causes your body to release less insulin, helping balance blood sugar levels and burn stored fat.
A meta-analysis published in the Journal of the American Diabetic Association that included a total of 13 studies found that, according to patients’ self-reported health markers, their hemoglobin A1c, fasting glucose and some lipid fractions (triglycerides) improved when consuming lower carbohydrate-content diets.
To be fair, however, Atkins isn’t the only type of plan to produce these results. Other types of diets have also been shown to benefit those with diabetes, such as the Mediterranean diet , even when more unprocessed carbs are included.
3. May Normalize Triglyceride and Cholesterol Levels
The Atkins diet is high in fat, specifically saturated fats that many fear contribute to heart problems. However, when saturated fat comes from healthy sources, such as grass-fed beef or coconut oil, it can actually be beneficial for raising HDL cholesterol levels and lowering risk factors for cardiovascular problems.
Eating a balanced, unprocessed diet that results in healthy weight loss can also be vital in lowering LDL cholesterol and high triglycerides , which are tied to heart disease and heart attacks.
4. Helps Treat Polycystic Ovarian Syndrome (PCOS)
One of the leading risk factors for polycystic ovarian syndrome (PCOS) is having diabetes or being prediabetic, due to the effects of insulin on hormonal balance. PCOS is now the most common endocrine disorder affecting women of reproductive age. It is associated with problems like obesity, hyperinsulinemia, infertility and insulin resistance.
While more research is still needed to draw conclusions, some studies have found that a low-carb ketogenic diet leads to significant improvement in PCOS symptoms — including weight, percent of free testosterone, LH/FSH hormone ratio and fasting insulin when followed for a 24-week period.
5. May Reduce Dementia Risk
Low-carb diets have been found to be beneficial for fighting cognitive problems, including dementia , Alzheimer’s and narcolepsy. Researchers believe that people with the highest insulin resistance might demonstrate higher levels of inflammation and lower cerebral blood flow (circulation to the brain), therefore less brain plasticity.
A 2012 report published in the Journal of Physiology found evidence of strong metabolic consequences on cognitive abilities like memory, mood and energy due to a high-sugar diet, especially when combined with a deficiency in omega-3 fatty acids . The study concluded that consuming omega-3 fatty acids and preventing insulin resistance may protect learning and memory by influencing brain-signaling mediators.
How to Follow It
What do you eat for breakfast on the Atkins diet? What can I eat for lunch on Atkins? Here’s an idea of what your week may look like if you chose a breakfast, lunch, dinner and snack each day from the lists below. These meals are appropriate for every phase, including the induction and balancing phases. During the pre-maintenance and maintenance phases you can add more fruits, starches and whole grains.
- Atkins Breakfast Ideas: two eggs with sauteed veggies and cheddar cheese; eggs with avocado, turkey bacon and spinach; keto pancakes; smoothie made with protein powder, greens and unsweetened almond/coconut milk.
- Atkins Lunch Ideas: Bunless turkey or beef burger with side salad; chef salad with chicken, bacon and avocado; veggie and cheese quiche; grilled fish with slaw and sauteed veggies; chicken, tuna or egg salad served over arugula.
- Atkins Dinner Ideas: Any of the lunches above; grilled chicken or salmon with roasted veggies and salad; stir-fry made with beef and broccoli; meatballs served with salad and tomato sauce.
- Atkins Snacks: shake made with collagen protein or bone broth and almond milk; hard boiled eggs; nuts/seeds/grain-free granola; carrots with blue cheese dip; olives and cheese; avocado and low-carb crackers.
- Acceptable beverages include coffee, tea, water, diet soda and herbal tea.
Atkins Diet Recipes
- 23 Low-Carb Breakfast Recipes
- 18 Low-Carb Meal Recipes
- 26 Low-Carb Snack Recipes
- 18 Low-Carb Dessert Recipes
- 50 Keto Recipes
Can Vegetarians Follow Atkins?
While the diet might be a bit restrictive for some, it’s possible to follow a plant-based , low-carb diet. Instead of eating animal products like eggs and meat, focus on plenty of low-carb, nutrient-dense vegan and/or vegetarian foods — like vegan protein powders, organic tofu/tempeh, nuts, seeds, low-carb fruits and veggies, leafy greens, healthy fats, and fermented foods. There’s also a similar plan called “Ketotarian,” which combines the keto diet with a vegetarian/vegan diet or pescatarian diet, supposedly for greater health benefits.
Risks and Side Effects
Why Atkins diet is bad for you, according to some skeptics? Although the Atkins diet does tend to produce substantial weight loss (at least initially), there isn’t necessarily a one-size-fits-all approach to low-carb dieting that is going to work best for everyone to improve health or quality of life. Losing weight isn’t everything, after all.
Your diet also has to be sustainable and actually beneficial for both your body and mind. Research suggests that if someone feels too restricted by his or her diet, that person is prone to gaining the weight back — and possibly even more than was lost in the first place.
Depending on factors like your medical history, age, gender, level of activity, bodyweight and genetic disposition, you may find the Atkins diet to either be very accommodating and rewarding or difficult to follow long term. Some studies have found that dieters on even very low-carb plans report less fatigue, cognitive symptoms, physical effects of hunger, insomnia and stomach problems compared to dieters on low-fat/higher-carb plans.
On the other hand, side effects are also possible when low-carb dieting. There seems to be a lot of variability when it comes to effects of the Atkins diet, ketogenic diet, etc.
The Atkins diet may cause possible side effects or worsened symptoms in some people (similar to the so-called keto flu , including:
- Fatigue or lethargy
- Trouble exercising due to weakness or loss of interest in being active due to feeling tired
- Trouble sleeping
- Digestive problems, such as constipation (usually due to low fiber intake)
- Indigestion due to eating too much fat
- Irritability or mood swings (which can occur when reducing carb intake, which impacts serotonin levels)
- Bad breath
Like with all dietary plans, it’s important to practice self-awareness if you plan to reduce your carb intake drastically for weight loss. This is especially true if you’re underweight, very active, elderly, have a hormone-related health condition, or you’re pregnant or breastfeeding. Pay attention to how you feel, your energy, sleep, moods and digestion in order to arrive at the level of carbs in your diet that works best for you personally.
- The Atkins diet has been around since the 1990s and is “low- or modified-carb diet” that’s high in fats and proteins but low in things like sugar, fruit, grains and many processed foods. The Atkins diet can help people lose weight and potentially improve certain health conditions.
- Benefits of the Atkins diet include losing weight, reducing diabetes risk, improving cholesterol and heart health, treating hormonal problems like PCOS, and protecting cognitive health.
- Risks or precautions to consider about the Atkins diet are the fact that many regain the weight lost after ending the diet, it can include too much saturated fat or protein for some people, may worsen digestion, and can feel restrictive.