When taking Wegovy (semaglutide 2.4 mg) for weight management, understanding how many calories you should eat is essential for safe, effective results. Rather than following a fixed calorie target, the recommended approach involves creating a personalised calorie deficit of approximately 600 calories per day below your maintenance requirements, in line with NICE guidance. Your individual calorie needs depend on factors including age, sex, current weight, activity level, and metabolic rate. Wegovy works by reducing appetite and increasing feelings of fullness, making it easier to adhere to a reduced-calorie diet. However, it must be used alongside lifestyle modifications—not as a standalone treatment. Professional guidance ensures your calorie intake supports sustainable weight loss whilst meeting nutritional requirements.
Quick Answer: There is no single calorie target for everyone on Wegovy; the recommended approach is to create a personalised calorie deficit of approximately 600 calories per day below your maintenance requirements, calculated with professional guidance.
Wegovy (semaglutide 2.4 mg) is a prescription medicine licensed by the MHRA for weight management in adults with a BMI ≥30 kg/m², or ≥27–<30 kg/m² with at least one weight-related comorbidity. It belongs to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, which work by mimicking a naturally occurring hormone that regulates appetite and food intake.
When considering calorie requirements whilst taking Wegovy, it's essential to understand that this medication is designed to be used alongside a reduced-calorie diet and increased physical activity—not as a standalone treatment. The medication enhances your body's natural satiety signals, making it easier to adhere to a calorie-controlled eating plan. However, there is no single "correct" calorie target for everyone on Wegovy, as individual requirements vary based on factors including age, sex, height, current weight, activity level, and metabolic rate.
NICE guidance emphasises that pharmacological interventions for weight management should be part of a comprehensive lifestyle modification programme. This means that whilst Wegovy can significantly reduce hunger and help control portion sizes, the foundation of successful weight loss remains a sustainable reduction in calorie intake combined with behavioural changes. Most healthcare professionals recommend a calorie deficit of approximately 600 calories per day below your maintenance requirements, which typically results in a gradual, sustainable weight loss of around 0.5–1 kg per week.
It's important to note that extremely low-calorie diets (below 800 calories daily) should only be undertaken under specialist medical supervision, as they can lead to nutritional deficiencies and other health complications, even when taking Wegovy.
In the NHS, Wegovy is typically prescribed within specialist weight management services and treatment is generally funded for up to 2 years, in accordance with NICE Technology Appraisal 875.
Rather than focusing on fixed calorie thresholds, the recommended approach when taking Wegovy is to create a personalised calorie deficit of around 600 calories per day below your maintenance requirements, in line with NICE guidance. This individualised approach is more appropriate than rigid calorie targets, as maintenance requirements vary significantly between individuals.
Your specific calorie target should be calculated based on your basal metabolic rate (BMR) and total daily energy expenditure (TDEE). Healthcare professionals often use validated equations such as the Mifflin-St Jeor formula to estimate your individual requirements, then subtract approximately 600 calories to create an appropriate deficit. Factors that influence your personal calorie needs include:
Current body weight and composition – heavier individuals typically require more calories
Age – metabolic rate generally decreases with age
Physical activity level – more active individuals need additional calories
Medical conditions – certain health issues affect metabolic requirements
Medications – some drugs influence metabolism and appetite
Whilst some general guidelines suggest minimum intakes of around 1,200 calories for women and 1,500 calories for men, these are not evidence-based for all individuals and may be inappropriate for many people. A more personalised approach under professional guidance is preferable, especially when taking Wegovy.
It's crucial not to reduce calories too drastically, even though Wegovy may significantly suppress your appetite. Very low calorie diets without medical supervision can lead to inadequate protein intake, vitamin and mineral deficiencies, muscle loss, fatigue, and metabolic adaptation that may hinder long-term weight management. The goal is sustainable weight loss that preserves lean muscle mass and supports overall health, rather than rapid weight reduction that may be difficult to maintain.
Consider consulting a registered dietitian for personalised advice on an appropriate calorie target that ensures nutritional adequacy whilst supporting your weight management goals.
Wegovy's active ingredient, semaglutide, works through multiple mechanisms to facilitate weight loss. As a GLP-1 receptor agonist, it binds to GLP-1 receptors in various tissues, including the brain, pancreas, and gastrointestinal tract. In the brain, semaglutide acts on areas that regulate appetite and food intake, particularly the hypothalamus and reward centres, leading to reduced hunger, increased feelings of fullness, and potentially decreased food cravings.
The medication also slows gastric emptying, meaning food remains in your stomach for longer periods. This physiological effect contributes to prolonged satiety after meals and helps reduce overall food consumption. Many patients report feeling satisfied with smaller portion sizes and experiencing fewer episodes of hunger between meals. Some individuals may also experience changes in food preferences, though this varies between patients.
Regarding metabolic effects, whilst Wegovy primarily works through appetite suppression rather than directly increasing metabolic rate, weight loss itself leads to changes in metabolism. As you lose weight, your basal metabolic rate naturally decreases because a smaller body requires fewer calories to maintain basic functions. This metabolic adaptation is a normal physiological response and occurs with any form of weight loss, not specifically due to Wegovy.
It's worth noting that Wegovy may cause gastrointestinal side effects, particularly during dose escalation. Common adverse effects include nausea, vomiting, diarrhoea, and constipation, which can temporarily affect your ability to consume adequate calories. If you experience persistent gastrointestinal symptoms that prevent you from eating sufficient nutritious food, contact your prescribing healthcare professional for advice on dose adjustment or symptom management strategies.
Wegovy may also increase the risk of gallbladder disease, including gallstones. Seek urgent medical attention if you experience severe right upper abdominal pain, fever, or yellowing of the skin or eyes. For people with diabetes who take insulin or sulfonylureas, Wegovy may increase the risk of hypoglycaemia (low blood sugar), so blood glucose monitoring and medication adjustments may be necessary.
If you experience any suspected side effects, report them to the MHRA through the Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.
A well-structured, nutrient-dense diet is essential when taking Wegovy to ensure you meet your nutritional requirements despite reduced calorie intake. The NHS Eatwell Guide provides an excellent framework for balanced eating, emphasising a variety of food groups in appropriate proportions.
Focus on foods that provide maximum nutritional value per calorie, emphasising lean proteins, vegetables, fruits, whole grains, and healthy fats. Protein intake is particularly important during weight loss to preserve muscle mass. If you require specific protein targets, a registered dietitian can provide personalised advice based on your individual needs and circumstances.
Your daily meal plan should include:
Lean protein sources (chicken, fish, eggs, legumes, low-fat dairy) at each meal to support satiety and muscle preservation
Non-starchy vegetables (leafy greens, broccoli, peppers, courgettes) which provide fibre, vitamins, and minerals with minimal calories
Whole grains in moderate portions (brown rice, quinoa, wholemeal bread) for sustained energy and fibre
Healthy fats in controlled amounts (olive oil, avocado, nuts, oily fish) for essential fatty acids and fat-soluble vitamin absorption
Adequate hydration – aim for 6–8 glasses of water daily, as dehydration can be mistaken for hunger
Fibre-rich foods – aim for at least 30g of fibre daily and include your 5-a-day of fruit and vegetables
Given that Wegovy reduces appetite, you may find it challenging to consume sufficient nutrients. Some people find that eating smaller, more frequent meals rather than three large meals helps them meet their nutritional targets, though this is a matter of personal preference rather than a requirement. Prioritise protein and vegetables at each eating occasion, and avoid "empty calories" from sugary drinks, alcohol, and highly processed foods that provide little nutritional benefit.
Meal timing can also influence your success. Some patients find eating their main meal earlier in the day helpful, whilst others prefer a lighter breakfast and more substantial evening meal. Experiment to find what works best with your Wegovy dosing schedule and lifestyle, remembering that consistency and nutritional adequacy matter more than specific timing patterns.
Regular monitoring is essential to ensure your calorie intake supports healthy, sustainable weight loss whilst taking Wegovy. NICE recommends that weight management interventions should aim for a loss of 5–10% of initial body weight, which has been shown to produce significant health benefits including improvements in blood pressure, cholesterol levels, and glycaemic control in those with type 2 diabetes.
Track your progress using multiple metrics rather than focusing solely on the scales:
Weekly weigh-ins at the same time of day, preferably in the morning before eating
Body measurements (waist, hips, chest) taken monthly to assess changes in body composition
Progress photographs to visualise changes that may not be apparent day-to-day
Energy levels and physical function – improvements in daily activities and exercise tolerance
Health markers – blood pressure, blood glucose, cholesterol (monitored by your healthcare team)
If you're losing weight too rapidly (more than 1 kg per week consistently), you may need to increase your calorie intake slightly to ensure adequate nutrition and prevent excessive muscle loss. Conversely, if weight loss plateaus for 3–4 weeks despite adherence to your plan, you might need to reassess your calorie intake or activity level. If plateaus persist despite adherence to your plan, consider scheduling a review with your prescriber or a registered dietitian. Remember that weight loss is rarely linear—fluctuations are normal due to factors including fluid retention, hormonal changes, and digestive contents.
Keep a food diary or use a reputable calorie-tracking application to maintain awareness of your intake. This practice helps identify patterns, ensures nutritional adequacy, and can highlight areas for improvement. However, avoid becoming overly restrictive or obsessive about tracking, as this can lead to disordered eating patterns. The goal is sustainable lifestyle change, not perfection.
The NHS Better Health website offers free resources to help you track your progress and maintain motivation throughout your weight management journey.
Whilst general guidance can be helpful, individualised professional advice is invaluable when taking Wegovy. You should seek support from a registered dietitian, Registered Nutritionist (UKVRN), or your prescribing healthcare professional in several circumstances.
Seek professional dietary advice if you:
Are unsure about appropriate calorie targets for your individual circumstances
Have pre-existing medical conditions (diabetes, kidney disease, cardiovascular disease) requiring specialised dietary considerations
Are taking multiple medications that may interact with nutritional status
Experience persistent gastrointestinal side effects affecting your ability to eat adequately
Have a history of disordered eating or eating disorders
Are losing weight too rapidly or experiencing concerning symptoms (excessive fatigue, hair loss, dizziness)
Have specific dietary requirements (vegetarian, vegan, food allergies, cultural preferences)
Are not achieving expected weight loss despite adherence to your plan
Contact your GP or prescribing clinician urgently if you experience severe or persistent vomiting, signs of dehydration, severe abdominal pain, or any symptoms suggesting pancreatitis (severe upper abdominal pain radiating to the back). Also seek urgent medical attention for symptoms of gallbladder disease, including severe right upper abdominal pain, fever, or jaundice.
Wegovy should not be used during pregnancy or breastfeeding. If you are planning a pregnancy, Wegovy should be discontinued at least 2 months before attempting to conceive. Discuss contraception and family planning with your healthcare provider while taking this medication.
NHS weight management services often provide access to dietitians as part of comprehensive programmes. Many areas offer tier 2 and tier 3 weight management services that include dietary counselling, behavioural support, and ongoing monitoring. Your GP can refer you to appropriate local services.
Remember that in the NHS, Wegovy is typically prescribed for up to 2 years in accordance with NICE guidance. Developing sustainable eating habits is crucial for maintaining weight loss. Professional dietary support helps you establish patterns that will serve you well both during treatment and after, should you eventually discontinue the medication. Investing in proper nutritional guidance maximises the benefits of Wegovy whilst protecting your overall health and wellbeing.
No, extremely low-calorie diets below 800 calories daily should only be undertaken under specialist medical supervision, as they can lead to nutritional deficiencies, muscle loss, and metabolic complications even when taking Wegovy. A personalised calorie deficit of approximately 600 calories below maintenance is recommended for sustainable, healthy weight loss.
Professional dietary advice from a registered dietitian is highly recommended, particularly if you have pre-existing medical conditions, experience persistent side effects affecting food intake, have a history of disordered eating, or are unsure about appropriate calorie targets for your individual circumstances.
Contact your prescribing healthcare professional if you experience persistent gastrointestinal symptoms such as nausea, vomiting, or diarrhoea that prevent adequate food intake. Dose adjustment or symptom management strategies may be necessary to ensure you can meet your nutritional requirements.
All medical content on this blog is created based on reputable, evidence-based sources and reviewed regularly for accuracy and relevance. While we strive to keep content up to date with the latest research and clinical guidelines, it is intended for general informational purposes only.
DisclaimerThis content is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional with any medical questions or concerns. Use of the information is at your own risk, and we are not responsible for any consequences resulting from its use.
