South Beach Diet: Complete Guide
Last updated: 20 February 2026
The South Beach diet is a phased eating plan created by cardiologist Dr Arthur Agatston. It emphasises “good” carbohydrates (low glycaemic index) and “good” fats (unsaturated), lean protein, and limits refined carbs and saturated fat. The South Beach diet has three phases: Phase 1 is strict low carb for about two weeks to kick-start weight loss; Phase 2 adds carbs back until you reach your goal weight; Phase 3 is lifelong maintenance. It is often used for weight loss and heart health. This guide explains what the South Beach diet is, its phases, what to eat and avoid, benefits and risks, and a sample day. This page is for education only. Talk to your doctor or dietitian before starting any diet, especially if you have a medical condition.
Disclaimer: The information on this page is for education only and does not replace advice from your doctor or dietitian. If you have heart disease, diabetes, kidney disease, or other conditions, get professional guidance before changing your diet.
Below: what the South Beach diet is, how the three phases work, what to eat and avoid, benefits and risks, a sample day, and answers to common questions. You can use our calorie calculator and TDEE calculator to tailor your intake if you combine South Beach with a weight goal.
What is the South Beach diet?
The South Beach diet is based on choosing carbohydrates that have a lower impact on blood sugar (low glycaemic index) and fats that support heart health (unsaturated oils, nuts, avocado), while limiting refined grains, sugar, and saturated fat. Unlike very low-carb plans that restrict most carbs long-term, the South Beach diet reintroduces “good” carbs in Phase 2 and 3, so it is often seen as more flexible and sustainable than strict Atkins or keto. It overlaps with principles of the DASH diet and heart-healthy diet–lean protein, vegetables, wholegrains, and healthy fats. There are no mandatory calories to count in the classic plan; portion control and food choice drive intake.
Core principles
- Phase 1: very low carb to reduce cravings and start weight loss.
- Phase 2 and 3: add “good” carbs (wholegrains, most fruits, legumes) and keep “good” fats and lean protein.
- Limit or avoid: refined carbs, sugar, full-fat dairy, fatty meats, and excess saturated fat.
How the South Beach diet works: phases
The South Beach diet has three phases (details can vary by book or programme):
- Phase 1 (about 2 weeks): Strict low carb–no bread, rice, pasta, fruit, or sugary foods. You eat lean protein, non-starchy vegetables, legumes, low-fat dairy, nuts, and healthy oils. The aim is to kick-start weight loss and reduce cravings for refined carbs.
- Phase 2: Add “good” carbs back gradually–wholegrains, more fruits, and some starchy vegetables–until you reach your goal weight. You stay in Phase 2 for as long as needed (weeks or months).
- Phase 3 (maintenance): Follow the South Beach principles for life. Choose good carbs and good fats, control portions, and avoid reverting to refined carbs and excess saturated fat. No strict carb limit–the focus is on quality and balance.
Weight loss still depends on a calorie deficit. Use our calorie calculator and TDEE calculator as a guide; discuss your plan with your doctor or dietitian. See our low-carb diet and weight loss diet guides for related approaches.
What to eat and what to limit
The table below is a general guide for the South Beach diet. Phase 1 is strictest; Phase 2 and 3 allow more foods.
| Eat (South Beach diet) | Phase 2 and 3 add | Limit or avoid |
|---|---|---|
| Lean meat, poultry, fish, eggs | Wholegrains (oats, brown rice, wholewheat bread in portions) | Refined carbs (white bread, white rice, sugary cereals) |
| Non-starchy vegetables; legumes | Most fruits (berries, apples, etc.) | Sugar, sweets, honey, sugary drinks |
| Low-fat dairy; nuts; avocado; olive oil | Sweet potato, other starchy veg in moderation | Full-fat dairy, fatty meats, excess saturated fat |
Phase 1 avoids all fruit and grains. In Phase 2 and 3, the South Beach diet favours low-GI carbs and healthy fats. For a similar heart-health focus with less structure, see our Mediterranean diet guide.
Potential benefits (with caveats)
Benefits are described in general terms–individual results vary. This is not medical advice.
- Weight loss: The South Beach diet can support weight loss by restricting refined carbs and calories in Phase 1 and teaching portion control and food quality in Phase 2 and 3. Loss is often noticeable in the first two weeks (partly water).
- Heart health: Emphasis on lean protein, vegetables, wholegrains, and unsaturated fats aligns with heart-healthy guidelines. Limiting saturated fat and refined carbs may help lipids and blood sugar in some people.
- Sustainability: Phase 3 allows a wide variety of foods, so some people find the South Beach diet easier to maintain long-term than very low-carb plans like keto.
Evidence: low-GI and low-carb approaches have been studied for weight loss and metabolic health. Diet does not replace medical care.
Risks and who should be cautious
The South Beach diet is generally moderate in structure but is not suitable for everyone.
- Phase 1: Very low carb can cause headaches, fatigue, or constipation in some people. Ensure enough fluid and fibre from allowed vegetables. If you have diabetes, medication may need to be adjusted–do not change your diet without your doctor’s advice.
- Kidney disease: Higher protein in Phase 1 may not be appropriate. If you have kidney disease, speak to your doctor or dietitian before starting the South Beach diet.
- Eating disorders: Phased rules and “good” vs “bad” food language can be unhelpful for some people with a history of disordered eating. Seek professional support if needed.
- Pregnancy and breastfeeding: Get advice before starting any restrictive phase.
Before starting the South Beach diet, talk to your doctor or dietitian.
Sample South Beach diet day (Phase 2 style)
This example fits Phase 2 or 3 of the South Beach diet–good carbs and good fats, lean protein. For Phase 1, omit fruit and wholegrains and keep to the Phase 1 list.
- Breakfast: Oatmeal with berries and a few nuts, or eggs with spinach and wholegrain toast. Low-fat milk or yogurt.
- Lunch: Salad with grilled chicken or chickpeas, olive oil, and a small wholegrain roll. Apple or other fruit.
- Dinner: Grilled fish or lean meat, brown rice or sweet potato, and vegetables. Use olive oil and herbs. Dessert: fruit or a small portion of dark chocolate if allowed in your phase.
- Snacks: Nuts, vegetable sticks, low-fat cheese, or fruit. Avoid sugary snacks and refined carbs.
Use our calorie deficit calculator with your doctor’s or dietitian’s guidance if you are aiming for weight loss. See our Atkins diet and DASH diet for related plans.
Frequently asked questions
The South Beach diet is a phased eating plan created by Dr Arthur Agatston. It emphasises ‘good’ carbs (low glycaemic index) and ‘good’ fats (unsaturated), lean protein, and limits refined carbs and saturated fat. Phase 1 is strict low carb for about 2 weeks; Phase 2 adds carbs back until goal weight; Phase 3 is maintenance. It is used for weight loss and heart health.
Phase 1 (about 2 weeks): very low carb to kick-start weight loss and reduce cravings. Phase 2: add back good carbs (wholegrains, some fruits) until you reach goal weight. Phase 3 (maintenance): follow the principles for life–choose good carbs and good fats, control portions. Exact rules can vary by book or programme.
In Phase 1: lean protein, non-starchy vegetables, legumes, low-fat dairy, nuts, healthy oils. No fruit, bread, rice, or sugary foods. In Phase 2 and 3: add wholegrains, more fruits, and continue lean protein and vegetables. Limit refined carbs, full-fat dairy, and saturated fat. See the article table for a full overview.
No. Both are phased and low-carb at the start. The South Beach diet focuses on ‘good’ carbs (low GI) and ‘good’ fats and allows more carbs in Phase 2 and 3. Atkins uses net carbs and keeps fat higher (including saturated). South Beach is often described as more heart-healthy and less restrictive long-term.
People with kidney disease, diabetes (without medical supervision), or a history of eating disorders should be cautious. Pregnant or breastfeeding women should get advice before starting. If you take medication that affects blood sugar, speak to your doctor before changing your diet.
Summary
The South Beach diet is a three-phase plan: Phase 1 (about 2 weeks) is strict low carb; Phase 2 adds “good” carbs until goal weight; Phase 3 is maintenance with an emphasis on good carbs, good fats, and lean protein. It limits refined carbs and saturated fat and is often used for weight loss and heart health. This page is for education only–talk to your doctor or dietitian before starting. See our Atkins diet, keto diet, DASH diet, and Mediterranean diet for related approaches. Use our calorie calculator and TDEE calculator with your healthcare team’s guidance.
Use our calculators with this diet
Set your calorie target and plan meals with our free tools.
You might also like
Other diet guides that may fit your goals.
DASH diet
Low sodium, plenty of potassium. Designed to support healthy blood pressure.
Mediterranean diet
Plant-forward eating with olive oil, fish and vegetables. Often recommended for heart health.
Low-carb diet
Fewer carbs, more protein and fat. Used for weight loss and blood sugar.
Heart-healthy & cholesterol diet
Limits saturated fat and sodium; supports heart and cholesterol.
Sources and further reading
This article is based on current guidance. For more detail, see:
- Official South Beach diet books and resources for phase rules and food lists
- Studies on low-GI and phased low-carb diets for weight loss and cardiovascular risk
- Guidance from dietetic associations on low-carb and heart-healthy eating
Last updated: 20 February 2026. Content is for educational purposes only and does not replace medical or dietetic advice.