Being underweight could be a sign that you’re not eating enough, getting the nutrients your body needs, or that you could be ill. If you’re underweight your GP can help with helpful diet advice, as well as reviewing why you might be underweight.
How to gain weight healthily
The first step to finding out whether you are underweight is calculating your BMI (body max index), this takes into account your height and sex to determine whether you are a healthy weight. If you are underweight there are foods you can eat and diets you can follow to help you gain weight.
It’s important to make sure that you increase the calories you are eating. An average man needs 2,500kcals a day and an average woman needs 2000kcals a day, dependent on their activity levels, to maintain their weight. Making sure that you are eating more than the recommended amount will help you to gain weight, however, be sure to make sure those extra calories are coming from healthy sources. You should aim to gain weight gradually until you reach a healthy weight for your height or a weight that you are happy with.
Healthy food to gain weight
If you’re trying to gain weight eating foods that are healthy and high in energy will not only help you to put on weight but will also give your body the vitamins and minerals it needs to work properly. Foods high in protein and natural fats support the body’s natural repair and build functions, helping you to grow muscle and put on weight.
Reaching for cakes, biscuits, crisps or sugary drinks may make you gain weight quickly but in doing so you could be harming your health and increasing your risk of developing type 2 diabetes. Instead aim to eat regular meals and snacks throughout the day, choosing from the main food groups – fruits and vegetables, starchy carbohydrates, dairy or dairy alternatives, and protein.
Planning your meals in advance will help you to track the number of calories you are consuming as well as make sure you are enjoying a varied diet. You could get the whole family involved with everything from planning a weekly menu to preparing healthy snacks.
Have a look at our meal ideas for more inspiration:
Breakfast – Have porridge made with full-fat milk topped with berries, fruit, or raisins. Add a pinch of cinnamon for a sweet flavor or mix in mashed banana. Top wholemeal toast with scrambled, poached, or eggs fried in a small amount of sunflower oil.
Lunch – Choose a jacket potato with baked beans or tuna, add a sprinkling of cheese to up your calorie intake. Make sure to pair it with a salad or some fruit afterward to help you reach your 5 portions of fruit or veg goal.
Snacks – Cut up an apple and dip the pieces into peanut butter, or reach for a handful of unsalted nuts or dried fruit between your meals.
Dinner – Base your meals around starchy carbohydrates, for example, eat pasta with tomato sauce and chicken served with a salad, or steak, potato wedges, and vegetables.
How can I put on weight fast?
Ideally, you should aim to put on weight at a gradual pace, however, if you are looking for a way to boost your weight gain and see results quicker you could try to:
- Eat more protein from sources such as lean meat, fish, beans, lentils, and eggs
- Eat more often – snack on dried or fresh fruit, homemade popcorn, rice cakes, or boiled eggs
- Increase your portion sizes – make sure you’re eating healthy balanced foods, including 5 portions of fruit or vegetables a day
- Fill up on foods high in good fats – Crush avocado on toast, or sprinkle seeds onto salads to add extra calories to meals. Also, use full-fat milk in your tea or add cheese to your meals.
The key to weight gain is to make these food changes part of your lifestyle, rather than view it as a diet these changes are ones that you can keep up for life.
If you are looking to gain weight in muscle mass alongside exercise, there are protein shakes and supplements that may be able to help alongside a healthy lifestyle and protein rich diet.
How long does it take to put on weight?
If you’re underweight, it’s important to visit your GP before changing your diet to rule out any underlying health issues. The aim of any weight gain or weight loss program should be gradual improvements. In order to gain more weight, you need to create an energy surplus which for women involves eating more than 2000 calories a day and for men more than 2500. It’s healthy to expect a weight gain of 1-2 pounds per week when energy intake levels are increased by about 500 calories a day.
It’s important to keep these additional calories as healthy as possible. Try to avoid relying too heavily on foods high in saturated fat and sugar as these will harmfully impact your body, leaving you at risk of developing conditions such as high cholesterol or blood pressure.
What counts as my 5-a-day?
One portion of fruit should weigh around 80g, which is the same as half a large grapefruit or two satsumas. A portion of dried fruit should weigh 30g, as dried fruit is higher in natural sugars and denser in energy. Your morning glass of fruit juice will also count towards your 5-a-day as long as it is unsweetened 100% juice and measures no more than 150ml.
What determines my weight?
There are a number of factors that contribute towards your weight, for example:
- Hereditary factors
- Hormonal abnormalities
- Lack of exercise
Weight tends to be influenced by a combination of factors, for example working in an office and not getting enough exercise could cause you to gain weight.
Can you gain weight without eating dairy?
Yes, if you are lactose intolerant or have decided to cut out dairy from your diet for other reasons you can still put on weight. Dairy alternatives such as soy, nut, and oat milk as well as coconut milk or vegan cheese, eaten as part of a balanced diet will help you to gain weight.