Atkins: the original low-carb diet won the race, then everyone caught up.
Long before keto had a hashtag, Atkins told the world to stop fearing fat and start fearing bread. It works, at first, about as well as anything. And a modified version has a serious medical job.
The short version
- What it is
- A staged low-carb diet: start at about 20 g of net carbs a day, then add carbs back step by step.
- Good for
- Quick early weight loss. As "modified Atkins", for drug-resistant epilepsy.
- Bad at
- Staying ahead. After a year the differences between diets mostly vanish.
- Evidence
- Moderate. Well studied, unspectacular long-term.
- Our take
- Not our plan, but our plan owes it a lot. We keep the low-carb, drop the steak worship.
What Atkins actually is
Atkins is the granddaddy of the popular low-carb diets, and the one your parents tried. Its core idea: cut carbohydrates hard, eat protein and fat freely, and you'll lose weight without counting calories.
Today's version, Atkins 20, starts with a strict phase at about 20 g of net carbs a day (net carbs means total carbs minus fibre).7 Over the following phases you add carbs back in small steps until you find the level where you keep losing or holding your weight.
The modified Atkins diet is a medical cousin, used for epilepsy. It's a less strict alternative to the classic medical ketogenic diet, with carbs limited but no weighing of fat and protein ratios.5
How it works in your body
In the first phase, Atkins is basically keto: carbs so low that your body empties its sugar stores, loses water, and starts burning fat and making ketones. Appetite tends to drop. That's why the first two weeks look so impressive on the scale.
As carbs come back, you leave ketosis and it becomes a general low-carb diet. From there, the weight loss works the usual way: you eat less because the food is filling and the junk is gone.
What you eat, what you don't
Eat
- Fish, eggs, poultry, meat
- Leafy greens, broccoli, courgette, peppers, cucumber
- Olive oil, avocado, butter and cheese in moderation
- Later phases: nuts, seeds, berries, legumes
- Later still: some whole grains and starchy vegetables
- Water, black coffee, tea
Forget it
- Sugar, soft drinks, juice, sweets
- White bread, pasta, rice, pastries
- Potatoes in the early phases
- Most fruit in the early phases
- Beer
- Branded "low-carb" bars and shakes as meals
A day on Atkins, early and late
Phase 1: eggs with smoked salmon and spinach for breakfast; a big salad with chicken, cucumber, peppers and olive oil for lunch; grilled fish with courgette and broccoli for dinner. Cheese as a snack, in moderation. Bacon is allowed. It isn't required.
Later phases: the same base, plus a handful of berries with Greek yoghurt in the morning, lentils or chickpeas in the salad, and a small portion of sweet potato or wholegrain at dinner. That's what Atkins looks like once it grows up, and it's the version worth keeping.
Atkins versus keto
Phase 1 of Atkins and keto are close relatives: both drop carbs low enough to push your body into ketosis. The difference is the direction afterwards. Keto aims to stay there. Atkins is a ladder: you climb out, adding carbs back step by step until you find the level that still works for you.7 Atkins also counts net carbs and doesn't ask you to hit a fat ratio. In practice, that makes later-phase Atkins easier to live with, and closer to a normal low-carb diet than to keto.
Alcohol on Atkins
OK, now and then
- Vodka, gin, whisky, tequila: neat, on ice or with soda water and lime
- One glass of dry red or white wine (later phases)
- Sparkling wine labelled brut nature or extra brut
Out
- Beer, cider
- Cocktails, liqueurs, sweet wine
- Anything with juice, cola, tonic or energy drinks
- "Zero" mixers: sweeteners are on our never list
50 Club: one light beer in the later phases, with food.
Alcohol puts fat burning on hold while your liver deals with it: two drinks cut it by about 73% in one study.9 All the details are in our alcohol guide.
What Atkins is good for, with proof
It won the head-to-head, at least once
In the A TO Z study, 311 women with overweight were randomly put on Atkins, Zone, Ornish or a standard diet for a year. Atkins came out ahead: about 4.7 kg lost, against 1.6 kg on the Zone diet, 2.2 kg on Ornish and 2.6 kg on the standard diet. Only the gap with Zone was statistically clear.1
Epilepsy, where the modified version is real medicine
The Cochrane review on ketogenic diets for drug-resistant epilepsy includes several trials of the modified Atkins diet. In two trials in children, about half of those on modified Atkins had their seizures cut by at least half, against about one in ten on usual care.5 The certainty of the evidence is low, and it's done with a specialist team. But it started with a handful of patients in 2003 and grew from there.6
The uncomfortable truth
"Atkins beats every other diet." Not for long. In another year-long trial, 160 people were put on Atkins, Ornish, Weight Watchers or Zone. Everyone lost a modest 2 to 3 kg, Atkins the least at 2.1 kg, and only about half of the Atkins group finished. The single best predictor of weight loss was how well people stuck to their diet, not which diet it was.2
A big meta-analysis of named diets came to the same place: low-carb diets like Atkins and low-fat diets lost about the same weight after a year, and differences between brands were small.3 The 2022 Cochrane review on low-carb versus balanced diets agrees.4
The risks
- Cholesterol. In long-term trials of very low-carb diets, LDL ("bad") cholesterol rose compared with low-fat diets.10 Atkins done with lots of red meat and butter makes that more likely. Get a blood test.
- What fills the gap. Low-carb diets heavy in animal fat and protein were linked with higher mortality in a large cohort study and meta-analysis; plant-based versions with lower.8
- Diabetes drugs. Phase 1 on insulin or sulfonylureas can cause lows. SGLT2 drugs with very low carbs can cause a dangerous acid build-up.11 Doctor first.
- Keto flu and constipation in the strict phase. Water, salt, vegetables.
- Dropout. About half didn't finish in the year-long trial.2
Allergies: watch the staples
| Atkins staple | Allergen (EU list of 14)12 | Swap |
|---|---|---|
| Eggs | Eggs | Fish, chicken, tofu |
| Cheese, cream, butter | Milk | Olive oil, avocado |
| Nuts (later phases) | Tree nuts, peanuts | Pumpkin and sunflower seeds |
| Fish, tuna | Fish | Chicken, eggs |
| Prawns, crab | Crustaceans | Fish, chicken |
| Branded bars and shakes | Often milk, soy, tree nuts | Real food |
| Mayonnaise, dressings | Eggs, mustard | Olive oil and lemon |
Don't do Atkins if you…
- are pregnant or breastfeeding
- have type 1 diabetes, or take insulin or SGLT2 drugs
- have kidney, liver or pancreas disease
- have high LDL cholesterol or heart disease, without your doctor
- have ever had an eating disorder
- are under 18 (modified Atkins for epilepsy only with a specialist team)
Healthen me asks about all of these and gives you a different plan if any apply.
How we use Atkins in your plan
We don't use Atkins itself; it's an info article for us. But its best idea lives on in our rules: cut sugar and refined starch, eat protein and vegetables first, bring better carbs back in sensible amounts.
Your first meal is keto-style, your other meals are low-carb. What we change: more fish, olive oil, vegetables and legumes, less red meat and butter. That's the version the evidence likes. For the "good carbs" twist on the same idea, see South Beach.
This article is general information, not medical advice. If you have a medical condition or take medication, talk to your doctor before changing how you eat.
Sources
- Gardner CD et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study. JAMA 2007;297(9):969–977. doi.org/10.1001/jama.297.9.969
- Dansinger ML et al. Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial. JAMA 2005;293(1):43–53. doi.org/10.1001/jama.293.1.43
- Johnston BC et al. Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis. JAMA 2014;312(9):923–933. doi.org/10.1001/jama.2014.10397
- Naude CE et al. Low-carbohydrate versus balanced-carbohydrate diets for reducing weight and cardiovascular risk. Cochrane Database of Systematic Reviews 2022;1:CD013334. doi.org/10.1002/14651858.CD013334.pub2
- Martin-McGill KJ et al. Ketogenic diets for drug-resistant epilepsy. Cochrane Database of Systematic Reviews 2020;6:CD001903. doi.org/10.1002/14651858.CD001903.pub5
- Kossoff EH et al. Efficacy of the Atkins diet as therapy for intractable epilepsy. Neurology 2003;61(12):1789–1791. doi.org/10.1212/01.wnl.0000098889.35155.72
- Atkins Nutritionals. Atkins 20, Phase 1. atkins.com/how-it-works/atkins-20/phase-1
- Seidelmann SB et al. Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis. Lancet Public Health 2018;3(9):e419–e428. doi.org/10.1016/S2468-2667(18)30135-X
- Siler SQ, Neese RA, Hellerstein MK. De novo lipogenesis, lipid kinetics, and whole-body lipid balances in humans after acute alcohol consumption. American Journal of Clinical Nutrition 1999;70(5):928–936. pubmed.ncbi.nlm.nih.gov/10539756
- Bueno NB et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. British Journal of Nutrition 2013;110(7):1178–1187. pubmed.ncbi.nlm.nih.gov/23651522
- US Food and Drug Administration. Drug Safety Communication: FDA warns that SGLT2 inhibitors for diabetes may result in a serious condition of too much acid in the blood, 15 May 2015 (archived copy). web.archive.org: fda.gov/Drugs/DrugSafety/ucm446845.htm Published case series: Mistry S, Cocks Eschler D. Euglycemic diabetic ketoacidosis caused by SGLT2 inhibitors and a ketogenic diet: a case series and review of literature. AACE Clinical Case Reports 2021;7(1):17–19. doi.org/10.1016/j.aace.2020.11.009 (PMC7924151)
- Regulation (EU) No 1169/2011 on food information to consumers, Annex II (the 14 allergens). eur-lex.europa.eu/eli/reg/2011/1169/oj