The safest way to lose weight is slowly and steadily, by eating a little less and moving a little more in ways you can keep up for good. The NHS advises aiming to lose 0.5 to 1 kg (1 to 2 lb) a week. For most people that means eating around 500 to 600 fewer calories a day than they burn, through smaller portions, more vegetables and protein, fewer sugary drinks and snacks, and more daily activity. Crash diets, very low-calorie plans without medical supervision, and weight loss pills bought online can be risky and rarely work long term. Your doctor can help, especially if you have a health condition.
Why slow and steady works best
- It’s more likely to last. Small changes you can keep up beat drastic ones you abandon.
- You lose more fat and less muscle, especially if you eat enough protein and stay active.
- It’s safer. Very rapid weight loss can cause tiredness, hair loss, constipation, gallstones and nutrient shortfalls.
- It gives your habits time to change, so you’re less likely to regain the weight.
Step 1: Check where you are
Body mass index (BMI) is a starting point. The NHS BMI calculator takes your height, weight, age and sex into account. Waist size matters too, because fat around the middle is linked with a higher risk of type 2 diabetes and heart disease. Talk to your doctor before starting if you have a health condition, take regular medicines, are pregnant, or have a BMI of 40 or more.
Step 2: Eat a little less, without going hungry
- Know roughly what you need. The NHS gives about 2,500 kcal a day for an average man and 2,000 kcal for an average woman to maintain weight. Our guide on how many calories you need explains how to estimate yours.
- Fill half your plate with vegetables or salad. They add volume and fiber for few calories.
- Include protein at every meal, such as fish, eggs, beans, lentils, chicken, tofu or Greek yogurt. It keeps you full.
- Choose whole grains over refined ones: oats, whole wheat bread and pasta, brown rice.
- Watch portion sizes of energy-dense foods such as oils, cheese, nuts, pastries and snacks.
- Cut sugary drinks and alcohol. They add calories without filling you up.
- Eat regular meals to avoid getting so hungry that you overeat later.
Our guide to building a balanced meal shows the proportions.
Step 3: Move more
Activity helps with weight loss and, even more, with keeping weight off and improving health. Adults are advised to do at least 150 minutes of moderate activity, such as brisk walking or cycling, a week, plus strength exercises on 2 days. Start with what you can manage and build up. The free NHS Better Health resources include a weight loss plan app, home workouts and the Couch to 5K running plan.
Step 4: Build habits that stick
- Make one or two changes at a time. Our guide on making healthy eating habits stick explains how.
- Keep a food diary for a week or two. Our guide to keeping a food diary shows what to record.
- Weigh yourself regularly, such as once a week at the same time of day, and focus on the trend.
- Plan meals and shop with a list.
- Sleep well. Short sleep is linked with increased appetite.
- Eat mindfully, without screens. Our guide to mindful eating explains how.
Which diet is best?
The best diet is one you can stick to that suits your health and preferences. Lower-fat, lower-carb, Mediterranean and intermittent fasting approaches can all work if they help you eat less overall. Our comparison of keto vs calorie counting shows that results are similar over a year.
Approaches to be careful with
- Very low-calorie diets (around 800 to 1,200 calories a day) can be effective, but the NHS says they’re not suitable for everyone, and you may be able to get support from a dietitian to follow one. Don’t try one on your own if you have a health condition.
- Slimming teas, diet pills and products that promise rapid results. Many don’t work, and some contain hidden drugs. Our article on weight loss supplements explains the risks.
- Prescription weight loss injections bought online without a prescription. Counterfeit products are a real danger. Weight loss medicines should only be prescribed and monitored by a health professional.
- Skipping meals or cutting out whole food groups without a plan can leave you short of nutrients and very hungry.
Getting support
A doctor can check for conditions that affect weight, such as an underactive thyroid or medicine side effects, and can refer you to local weight management services, a dietitian or, where appropriate, weight loss medicines or surgery. Having support, from a professional, a program or friends and family, makes weight loss more likely to succeed.
A note on your relationship with food
Weight loss shouldn’t come at the cost of your mental health. If dieting leads to bingeing, guilt, anxiety about food or eating, or very restrictive habits, or you’re losing weight when you’re already a healthy weight, talk to your doctor. An eating disorder is serious but treatable, and if you need someone to talk to now, findahelpline.com lists free helplines in many countries.
Common questions
How fast is too fast?
More than about 1 kg (2 lb) a week, after the first couple of weeks, is faster than generally advised unless you’re on a supervised medical program. Early weight loss is often partly water.
Why have I stopped losing weight?
As you lose weight, your body needs fewer calories, so the same diet causes slower loss. Review your portions, drinks and activity. Our guide to a weight loss plateau has more tips.
Do I need to count calories?
Not necessarily. Many people lose weight by changing habits, portion sizes and food choices without counting. Others find tracking helpful at first.
This article is general information, not medical advice. Talk to your doctor or a registered dietitian before making big changes to how you eat, especially if you have a health condition, take regular medication, or are pregnant or breastfeeding.
