The South Beach diet: Atkins with better manners. Sensible, but not special.
A doctor's answer to Atkins: cut the bad carbs, keep the good ones, swap butter for olive oil. Most of it is good advice. Very little of it was ever tested as "South Beach".
The short version
- What it is
- A three-phase low-carb diet that keeps "good carbs" (low GI) and "good fats".
- Good for
- A gentler, more balanced low-carb than Atkins. Getting people off white bread.
- Bad at
- Evidence of its own. Weight loss ends up about the same as other diets.
- Evidence
- Weak for the brand, moderate for its ingredients.
- Our take
- Not our plan, but close to our thinking. We just skip the book.
What the South Beach diet actually is
The South Beach diet comes from a 2003 bestseller by Arthur Agatston, a US doctor.1 It was pitched as a heart-friendlier answer to Atkins: still low in carbs, but with lean protein instead of bacon, olive oil instead of butter, and room for "good carbs".
It runs in three phases.1 Phase 1 lasts two weeks and is the strictest, with most carbs cut out. Think vegetables, lean protein and good fats. Phase 2 brings back whole grains, fruit and other "good carbs", step by step, until you reach your target weight. Phase 3 is maintenance, for life.
How it works in your body
South Beach leans on the glycaemic index (GI): a measure of how fast a food raises blood sugar compared with pure glucose. The idea was first set out in 1981, when researchers tested 62 foods and found big differences, with legumes and dairy raising blood sugar far less than cereals and many starchy foods.2
Low-GI foods, such as lentils, most vegetables and whole grains, release sugar slowly. High-GI foods, white bread, white rice, potatoes and sugar, hit fast. Smaller blood sugar swings may mean less hunger and fewer cravings. Combine that with lots of protein and vegetables, and most people simply eat less.
What you eat, what you don't
Eat
- Fish, chicken, turkey, eggs, tofu
- Vegetables of all kinds (except potatoes in phase 1)
- Olive oil, avocado, nuts
- Lentils, beans, chickpeas
- From phase 2: whole grains, berries, apples, citrus
- Low-fat yoghurt and cheese
Forget it
- Sugar, soft drinks, juice
- White bread, white rice, pastries
- Potatoes in phase 1
- Fatty processed meat
- Butter as your main fat
- Any fruit in phase 1
A day on South Beach
Phase 1: scrambled eggs with peppers and mushrooms; at lunch, grilled chicken on a big green salad with olive oil; a handful of almonds in the afternoon; in the evening, baked fish with ratatouille and a scoop of lentils. No fruit, no bread, no rice. You'll miss them by Thursday.
Phase 2: the same backbone, plus some of the carbs back. Plain yoghurt with berries and oats in the morning, a slice of wholegrain bread with lunch, brown rice or a small sweet potato with dinner, an apple as dessert. This is the version that's meant to last, and it's basically a sensible everyday diet.
South Beach in Singapore and in Austria, Germany and Switzerland
Singapore: Phase 2 fits neatly with the government's My Healthy Plate: half fruit and vegetables, a quarter wholegrains, a quarter protein.9 Ask for brown rice where the stall has it, choose sliced fish soup, steamed fish or yong tau foo in clear soup, and order tofu and greens at the economy rice stall. Phase 1 traps: rice, noodles, roti prata, kaya toast and sweetened kopi.
Austria, Germany, Switzerland: good matches are grilled fish or chicken with salad, Linsensuppe (lentil soup, without sausage), Vollkornbrot from phase 2, and plain Joghurt or Quark with berries. Traps: white Semmeln and Brötchen, Rösti, Spätzle, Schnitzel in breadcrumbs and the bakery counter in general.
Alcohol on the South Beach diet
OK, now and then
- From phase 2: a glass of dry red or white wine with a meal
- Spirits with soda water and lime
Out
- Any alcohol in phase 1
- Beer, cider, sweet wine
- Cocktails, liqueurs
- Anything with juice, cola or tonic
50 Club: one glass of dry wine with dinner, from phase 2.
Alcohol pauses fat burning while your liver deals with it: two drinks cut it by about 73% in one study.5 All the details are in our alcohol guide.
What the South Beach diet is good for, with proof
Weight loss, like other named diets
South Beach was one of the low-carb brands included in a big 2014 meta-analysis of named diets. Low-carb diets as a group led to about 8.7 kg more weight loss than no diet at six months and about 7.3 kg at a year, very close to low-fat diets.3 Good news if you want to lose weight. Not proof that South Beach beats anything.
Low-GI eating: small benefits
The Cochrane review of low-GI diets for overweight found slightly more weight loss (about 1 kg) and a small drop in LDL cholesterol compared with other diets.4 The catch: only six small trials, and the longest lasted six months. Promising, not proven.
Better fats than Atkins
Swapping butter and fatty meat for olive oil, fish and nuts is one thing South Beach got clearly right. In a large cohort study, low-carb diets built on plant fats and proteins were linked with lower mortality, and those built on animal fats and proteins with higher.6
The uncomfortable truth
"South Beach is scientifically proven." The book is built on real ideas: low GI, unsaturated fats, fewer refined carbs. But we found almost no trials of the South Beach diet itself. Its success is the success of its ingredients, which are freely available without the book.
And the phase 1 weight loss? Mostly water, like every strict low-carb start. Phase 2 is where real life begins.
South Beach or Mediterranean?
Phase 2 and 3 of South Beach look a lot like the Mediterranean diet: vegetables, fish, olive oil, nuts, legumes, some whole grains. The difference is that the Mediterranean diet has been tested on its own. In the PREDIMED trial, 7,447 older adults at high heart risk who ate a Mediterranean diet with extra olive oil or nuts had about 30% fewer heart attacks, strokes and heart deaths over about five years than people told to eat low-fat.10 The trial was retracted and republished in 2018 after randomisation problems; the corrected result held. If you like the South Beach plate, you can skip the phase 1 misery and just eat Mediterranean.
The risks
- Few, if you follow it as written. It's one of the more balanced low-carb diets.
- Phase 1 side effects: tiredness, headache, low energy for training, like a mild keto flu.
- Diabetes drugs. Cutting carbs hard in phase 1 lowers blood sugar. On insulin or sulfonylureas, doses may need adjusting. SGLT2 drugs and very low carbs can cause a serious acid build-up.7
- "Low-fat" products. Some versions push low-fat dairy and branded products. Check labels for added sugar and sweeteners.
Allergies: watch the staples
| South Beach staple | Allergen (EU list of 14)8 | Swap |
|---|---|---|
| Eggs | Eggs | Chicken, tofu, fish |
| Low-fat yoghurt, cheese | Milk | Soy yoghurt, hummus |
| Nuts | Tree nuts, peanuts | Pumpkin and sunflower seeds |
| Fish, prawns | Fish, crustaceans | Chicken, turkey, lentils |
| Whole-grain bread, oats | Cereals containing gluten | Quinoa, buckwheat, brown rice |
| Tofu, soy | Soy | Chickpeas, eggs |
| Hummus | Sesame (tahini) | Bean dip without tahini |
Don't do South Beach on your own if you…
- take insulin, sulfonylureas or SGLT2 drugs
- are pregnant or breastfeeding
- have kidney disease
- have ever had an eating disorder
- are under 18
Healthen me asks about all of these and gives you a different plan if any apply.
How we use South Beach in your plan
We don't use the brand; it's an info article for us. But a lot of our rules will feel familiar: low-carb meals built on vegetables, protein and olive oil, "better carbs" like legumes and brown rice in modest portions, and a red list with sugar, soft drinks and white bread on it.
Where we differ: no two-week crash phase, an eating window instead of three meals plus snacks, and a keto-style first meal. Meal order helps too; see glucose-spike techniques. If blood sugar is a medical issue for you, read low GI and diabetic eating.
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
- Agatston A. The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss. Emmaus, PA: Rodale, 2003.
- Jenkins DJ et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. American Journal of Clinical Nutrition 1981;34(3):362–366. doi.org/10.1093/ajcn/34.3.362
- 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
- Thomas DE et al. Low glycaemic index or low glycaemic load diets for overweight and obesity. Cochrane Database of Systematic Reviews 2007;(3):CD005105. doi.org/10.1002/14651858.CD005105.pub2
- 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
- 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
- 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
- Health Promotion Board Singapore (HealthHub). Nutritious foods for a healthy diet: My Healthy Plate. healthhub.sg/programmes/nutrition-hub/eat-more
- Estruch R et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. New England Journal of Medicine 2018;378(25):e34. doi.org/10.1056/NEJMoa1800389