What should my caloric intake be for weight loss?

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Most adults should eat 600 fewer calories per day to lose weight. But there's more to weight loss than calories alone. Learn why in our guide.


Most adults should eat 600 fewer calories per day to lose weight. But there's more to weight loss than calories alone. Learn why in our guide.

Anyone who's tried to lose weight knows it's rarely easy. For many of us, it means unlearning old habits, changing our diets and getting used to a regular exercise regime.


And let's not forget the hardest hurdle of all: sticking to this new routine for life.


With all these factors to think about, it might surprise you to learn that weight loss – on a biological level – is very basic indeed.


When we consume energy (measured in kcal or calories), our bodies store that energy as fat. When we reduce our calorie intake by eating less or burn calories by exercising, our bodies start using up those fat reserves. Over time, this leads to weight loss.


That's the formula. More calories equals weight gain. Fewer calories equals weight loss.


With that in mind, you might wonder how many calories you should eat for weight loss.


The straightforward answer is that you should aim to cut your usual calorie intake by about 600 calories per day.¹ For most people, that tends to result in a safe and sustainable rate of weight loss.


However, there's more to weight loss than just counting calories. Let's learn more about maintaining a calorie deficit and the importance of eating a healthy, balanced diet.


How many calories should I eat a day for weight loss?


The recommended daily calorie intake for men is 2,500kcal. For women, it's 2,000kcal.¹


To lose weight, the NHS recommends reducing your daily calorie intake by about 600kcal.¹ If we take the recommended intake as a baseline, that means:


  • Most men should eat around 1,900 daily calories to lose weight.
  • Most women should eat around 1,400 daily calories to lose weight

The idea is to burn more calories through exercise and daily activities than you gain by eating food. When we burn more calories than we consume, this is called a 'calorie deficit'.


For most people, cutting 600 calories a day leads to weight loss of around 0.5kg to 1kg (1lb to 2lbs) per week.² This is considered a safe and sustainable rate of weight loss.


Picture of a person standing on scales.

However, it's important to note that the NHS's recommendation is a general guideline. We all have different daily calorie requirements, and these can vary depending on several factors. That includes:


  • Your age
  • Your assigned sex at birth
  • Your weight and height
  • Your activity level
  • Your metabolism (how quickly you burn calories)
  • Medical conditions you might have – hyperthyroidism, for instance, can slow your metabolism

Eating too few calories can be hard to maintain and can cause side effects like constipation, headaches and fatigue. That's why it's important to get advice from medical professionals if you're unsure how many calories you should eat to lose weight.


How many calories do I need for weight loss when taking Wegovy or Mounjaro?

The guidelines are the same for people using injectable weight loss medications like Wegovy and Mounjaro.


There's a simple reason for that. While these injections are effective for most people, they don't burn fat. Instead, they mimic natural hormones that limit your appetite and help you feel full after eating.


That can make Wegovy or Mounjaro a useful helping hand for weight loss because they can help you control food cravings and portion sizes. However, you should still aim to cut your calorie intake just as if you were dieting normally.


If you take these medications alongside a healthy diet and regular exercise, you can expect to lose:


  • Around 15% of your body weight with Wegovy³
  • Around 21% of your body weight with Mounjaro⁴

Are calories everything?

On the surface, it all seems quite simple. If you eat fewer calories than you burn, you will lose weight – though it takes longer for some people than others.


But calories aren't everything. They only measure the energy levels of food – not its nutritional content.


To stay healthy, we all need to eat a balanced diet that's rich in essential nutrients like vitamins and minerals. If you only pay attention to calories, you risk missing out on these nutrients.


In the short term, that can lead to ill effects like feeling tired, digestive issues and hair thinning. Long-term health consequences, meanwhile, can include a weakened immune system, bone health problems and an increased risk of heart disease.


On top of that, it's important to combine your calorie-cutting with increased physical activity. Regular exercise boosts your metabolism in the long term, so you lose weight more quickly as time goes on.


Picture of a person doing exercise.

It's good for your overall health, too. Exercise strengthens your bones, heart and muscles, reduces the risk of serious illnesses like heart disease and can even boost your mood.


How to cut calories safely

Here are some tips to help you lose weight safely and sustainably while maintaining a calorie deficit.


  • Eat a balanced, nutrient-rich diet: aim to eat a sensible variety of foods from all food groups. That includes fruits and vegetables, high-fibre carbohydrates, protein, healthy fats, and dairy or dairy alternatives. The NHS Eatwell Guide can help you build a balanced plate.
  • Cut simple carbs: swap white bread, rice and pasta for wholemeal alternatives. These have a higher fibre content, which helps you feel full for longer.
  • Avoid 'empty calories': some foods are dense in calories but have little or no nutritional value. Examples include sugary drinks, desserts, chocolate, crisps and many pre-packaged meals.
  • Fill up on the right foods: a plateful of vegetables or salad will fill you up without piling on the calories. When you're mindful of your food choices, you're more likely to stay satisfied and stick to your healthy eating routine.
  • Drink plenty of fluids: staying hydrated is good for you and can help suppress appetite cravings. The NHS recommends drinking 6 to 8 glasses of water or sugar-free drinks per day.⁵
  • Exercise within your limits: adults aged 19 to 64 should aim to do at least 150 minutes of moderate-intensity exercise each week.⁶ But be careful not to rush into it. If you do too much, too fast, you risk burning out and giving up before you can feel the benefits.

Should I count calories?

It's up to you.


Some people find that counting calories helps them manage their eating habits and track their progress. But you can get the same results by practising good portion control and sticking to lower-calorie, nutrient-rich foods.


What's most important is that you eat a healthy, balanced diet, stay active and have fun doing it. Remember that a healthy diet doesn't have to mean eating bland, boring meals. If you cook up a wide variety of foods and find the fun in your dietary regime, you're more likely to form habits that stick. Good luck!


As part of Phoenix Health, SemaPen has helped people in the UK lose weight for more than 20 years. If counting calories isn't working for you, why not learn more about our clinically proven, expert-led weight loss programmes?


Sources

1. NHS (n.d.) Calorie Counting. Retrieved from https://www.nhs.uk/better-health/lose-weight/calorie-counting/

2. NHS (2023) Treatment: Obesity. Retrieved from https://www.nhs.uk/conditions/obesity/treatment/


3. Wilding, J.P.H. et al. (2021) "Once-weekly semaglutide in adults with overweight or obesity" The New England Journal of Medicine,

384(11) https://doi.org/10.1056/NEJMoa2032183


4. Jastreboff, A.M. et al. (2022) "Tirzepatide Once Weekly for the Treatment of Obesity" The New England Journal of Medicine, 387(3) https://doi.org/10.1056/NEJMoa2206038


5. NHS (2022) The Eatwell Guide. Retrieved from https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/the-eatwell-guide/


6. NHS (2024) Physical activity guidelines for adults aged 19 to 64. Retrieved from https://www.nhs.uk/live-well/exercise/physical-activity-guidelines-for-adults-aged-19-to-64/


This article was reviewed and approved by Lujain Alhassan, Bariatric Dietitian, and Sarah Abdula, Specialist Dietitian, on 27 November 2025.


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