Maintaining Healthy Body Weight

This article discusses Maintaining Healthy Body Weight for Adults. To learn more about a Healthy Body Size for Children read this excellent article by Health Navigator.

Being a healthy weight can improve our quality of life as well as help us to live longer. Maintaining a healthy body weight makes moving around easier, and is kinder to our hearts, muscles and bones. It also lowers the risk of developing type 2 diabetes and heart disease.

In simple terms, weight gain happens when we eat and drink more than the amount of energy we use. Consuming more energy (kilojoules/calories), than you burn no matter what food it comes from, leads to weight gain. However, genetics, medical conditions, medications, socioeconomic status all play a role in determining your body size. Different people can eat the same food and do the same physical activity and yet be at different body sizes.

Body size is just one marker of health, other more important markers include

  • Balanced eating patterns with plenty of veg and fruit
  • Fitness levels
  • Sleep
  • Not smoking, and not drinking too much alcohol
  • Blood tests (e.g., blood lipids, blood sugar), blood pressure
  • Body composition (how much muscle and fat you have)

So what is a healthy weight?

One way of measuring weight status is BMI (Body Mass Index). BMI has four categories, indicating whether a person is underweight, healthy weight, overweight or obese. It is calculated using your weight and height measurements.

However, your BMI doesn’t take into account your body composition (amount of fat and muscle) or where the fat is stored.

Waist measurement is a better tool as it measures the amount of abdominal fat (fat stored around your waist) which is a risk factor for heart disease present in the body. A good rule of thumb is that a healthy waist measurement should be less than half your height – for children as well as adults.

Learn more about your BMI and waist measurement.

If you are concerned about your weight, it is worth talking to your GP. They can recommend extra tests e.g., cholesterol levels and blood sugar levels to learn more about your risk of disease.

What is a safe rate of weight loss?

Weight loss between 0.5kg -1kg per week is considered safe and sustainable, keeping in mind that that weight loss will be slower if you have a smaller amount to lose.

There are certain conditions where is it is unsafe to lose weight (regardless of your starting weight)

  • Serious illnesses e.g., cancer, kidney failure
  • Eating disorder

In older age groups (70+), a higher BMI can actually be protective- e.g., extra fat tissue can help cushion falls. Always speak to your doctor before making significant dietary and lifestyle changes.

What changes can I make?

We recommend slow steady weight loss by making small changes to your eating habits  – it took a long time for the extra kilograms to be put on, it will take as long (or longer) to lose them. Small but consistent changes have been found to be effective in keeping those extra kilograms off in the long term.

Diets encouraging you to cut out a large number of foods, such as very low carbohydrate diets, may result in quick weight loss initially but are unlikely to be a long-term solution. These types of diets may also be low in fibrevitamins and minerals, putting you at risk nutritionally. Speak to a dietitian before starting any restrictive diets.

Tips for sustainable weight loss

Vegetables and Fruit

  • Fill up on veg! Vegetables are very low in calories but have a lot of fibre which fills you up. They are also jam-packed with vitamins, and minerals which your body loves!
  • Aim to eat at least 5 servings of vegetables a day.
  • Fruit provides us with similar vitamins, minerals, and fibre to vegetables. Fruit provides us with more energy (kilojoules/calories) (mainly from carbohydrates). Aim to eat 2 pieces of fruit a day (at least).


  • Including protein in each meal helps keep you feel fuller for longer and strength training helps to reduce the loss of muscle mass
  • Protein-rich foods include meat, chicken, fish, low-fat cheese, eggs, milk, yoghurt, tofu, legumes (chickpeas, kidney beans, lentils, etc.)


  • Carbohydrates often get a bad rap, but whole grain and high fibre carbs provide fibre, essential vitamins, and minerals, and support gut health, overall health, and energy levels.
  • It is important to focus on the type of carbohydrates and portion size.
  • Type: Choose high-fiber-carbohydrate such as wholegrain pasta and bread, lentils and legumes, potato and kumara with the skin-on
  • Portion size: The general recommendation is a fist-sized amount of carbohydrates at each meal, however, this depends on each individual. You might need more on more active days, and less on less active days.
  • Minimize refined carbohydrates (white bread, cakes, pastries) and added sugars as they contain a lot of energy but lack fibre and other nutrients.
  • Choose no added sugar varieties or low sugar varieties of foods like yoghurt, muesli bars, and cereals.


  • Fat is an important part of the diet and also helps us feel full. In saying that, compared to protein and carbohydrates, per gram, fat provides us a lot of kilojoules/calories (energy).
  • With fat, a little goes a long way. Stick to roughly a thumb-sized amount at meal times. If cooking with oil, use an oil spray or a spoon, rather than pouring from the bottle. Trim any visible fat from meat and remove the skin from poultry before eating.
  • Many kinds of cheese are high in fat. Choose lower-fat options, such as edam, cottage cheese, and lite cream cheese, or simply use smaller amounts of the regular varieties.
  • Swap standard (blue top) milk for either lite (light blue) or trim (green) options.
  • All types of fat provide us with the same amount of kilojoules/calories (energy). However, choosing healthy fats such as avocado, extra virgin olive oil, nuts & seeds, and oily fish over unhealthy fats such as fatty meat, processed meat, and ultra-processed foods like chips and biscuits is key to overall health.

Using the Healthy Plate Model is a great way to ensure you are getting a good balance of different nutrients

  • ½ plate (~2 handfuls) of non-starchy vegetables: the more colour the better (non-starchy veggies include tomato, leafy greens, mushrooms, and eggplant whereas starchy vegetables include potato, kūmara, and yams)
  • ¼ plate (~1 closed fist) carbohydrate ideally high fibre e.g., wholegrain pasta, brown rice, potato/kūmara with the skin-on.
  • ¼ plate source of protein: e.g., lean meat or beans or eggs.
  • Total fat in a meal should equate to roughly a thumb-sized amount: choose mainly heart-healthy fat e.g., olive oil, or avocado.
  • Check out this Portion Size Guide by the Heart Foundation. Using a smaller plate can help with reducing portion sizes.

Snacks, ultra-processed foods/takeaway foods.

  • Eat less high-fat takeaways and snacks. Limit buying takeaways to once a week. Biscuits, cakes, sweets, chocolate, butter, and margarine all contain a lot of calories and are low in nutrients. One way to reduce eating these foods is to take them off the supermarket list. If they are not in the fridge or cupboard then they are not available to eat.
  • Snacks: Try yoghurt and some fruit, a glass of trim milk, a small handful of nuts, and dried or fresh fruit.


  • Make water your best friend! Water is the best option for rehydrating the body. To make water more appealing try keeping a jug in the fridge, and flavour with lemon or lime juice. Drinks such as fruit juices, and fizzy drinks contain a lot of sugar lack but don’t really fill you up, making them very easy to over-consume. Swapping regular fizzy drinks to diet/no sugar varieties is a good way to reduce your energy (calorie/kilojoule) intake.
  • Alcohol is a significant source of calories and does not provide us with any nutrition so aim to keep alcohol consumption to a minimum. If you do drink, learn how to do so safely here.

How to eat

  • Eat slowly – it takes 20 minutes before your brain realises you are full, so wait a while before having a second helping. (Health Navigator: Tips on Mindful Eating)
  • Minimize distractions – turn off your TV or phone so that you can pay closer attention to your fullness cues.


  • When it comes to making any healthy changes, mindset is key.
  • There is no need to cut out your favourite, more indulgent foods such as chocolate, and chips. Include the ones you really enjoy- and eat them in small portions and focus on savouring them and eating them mindfully. This reduces the feeling of restrictions and makes healthy eating more sustainable.
  • Think of what you can add in rather than take out. For example, if you are having a hamburger, bulk it out by adding a generous serve (~2 handfuls) of veg e.g., crispy lettuce, juicy tomato, beetroot, or some tasty grilled mushrooms to the side.

Note these are general recommendations and may need to be tweaked depending on the individual. A dietitian or registered nutritionist can offer you personalized recommendations to support sustainable weight loss and optimize the quality of your diet.

Being Active

Being active not only supports weight loss efforts but also strengthens your heart, and your bones and improves mental health. Be more active in every part of your day – around the house, at school, or at work as it all adds up. Ideally aim for 30 minutes or more of activity every day. Aim for a mix of resistance (weight-bearing) exercise and cardio (walking, running) throughout the week. Planned activity helps you be even more active. As your fitness improves, gradually increase the amount. Whatever exercise you choose, it must be fun and enjoyable to keep you motivated. Read our physical activity page for more information and some activity ideas.

More info

Last reviewed: 3 August 2022

Last modified: August 2, 2022