It seems like everyone is obsessed with losing weight, but what happens if you want to gain weight? The term ‘underweight’ is typically used to describe an individual who is not within a healthy weight range and has less body fat than is required for maximum well-being. Body fat is estimated using a measurement known as Body Mass Index (BMI), which classifies a person as underweight if their BMI is below 18.5.
Whilst there are some people who have a naturally slender body type, those who are underweight as a result of poor nutrition or a health issue stand a significant risk of developing certain health problems.

If you are underweight, aiming to gain weight safely until you are within a healthy range for your age and height will help to reduce any health risks. Visit the hospital beforehand so they can rule out any underlying medical causes for low weight as well as providing you with some useful medical advice.

Household scales can be helpful to track your weight, but they rarely tell the whole story. They aren’t sophisticated enough to determine if the fat percentage in your body is appropriate for your height. If you are concerned that you are underweight, then the best way to measure this is to calculate your BMI. Anything between 18.5 and 24.9 is a healthy weight, and anything above or below poses significant health risks. BMI reference ranges were developed for use with adults only, with separate charts available for children. Be aware that these markers could be inaccurate for women that are breastfeeding or pregnant, people that are frail or for those who have a high muscle percentage
Obtaining a healthy weight is one of the most important targets for anyone who is underweight. Yet it isn’t the only reason individuals want to gain weight, as you might want to build muscle mass for sports, might be recovering from an illness, amongst others.

Listed below are a few tips tailored for people who are underweight:

  • Eat regularly and healthy. If we eat the right amount of calories this means consumption and energy use will be balanced and our weight will remain the same Eating five or six smaller meals per day when you are underweight can be more manageable compared with the standard three since satiety is felt faster than an individual with healthy weight .

  • Avoid soft drinks and caffeine-heavy coffee that adds little nutritional value to your diet. Try milk, fruit juices, healthy shakes, fruits, vegetables, nuts, seeds, whole grain cereals, bread and pastas, lean meats and dairy products instead as they will help increase the energy in your diet and also add important nutrients for your health too.
  • Don’t drink before meals. Fluids before meals can affect your appetite. Try limiting drinking until 30 minutes after you’ve eaten.
    Snack healthy. Snacking on avocados, nuts, cheese, peanut butter or dried fruits between mealtimes can be a good way to gain weight.
  • Treat yourself. Even when underweight it’s fine to have an unhealthy treat every now and then. But be mindful of excess fat and sugar – try to keep most treats nutritious and healthy.
  • Work out. Strength training (building muscle) can help you gain weight. Exercise may also help you get your appetite back. Find out your body mass index (BMI) and monitor it regularly.
  • Get quality sleep. Sleeping properly is very important for muscle growth.
  • Eat more proteins. Eat your protein first and vegetables last. If you have a mix of foods on your plate, eat the calorie-dense and protein-rich foods first. Eat the vegetables last.
  • Avoid cigarettes: Smokers tend to weigh less than non-smokers, and quitting smoking often leads to weight gain.

To calculate your BMI :
First, find your weight in kilograms and your height in metres – e.g. weight = 50 kg height = 1.8
Multiply your height by itself – e.g. 1.8 x 1.8 = 3.24
Divide your weight by that figure – e.g. 50 ÷ 3.24 = 15.4
15.4 is a BMI that is below the healthy body weight range.

In addition to the physical issues that may be caused by low weight, some individuals may also be affected on a psychological level. Our self image plays an important part in both our confidence and self-esteem and feeling unhappy with weight and image can lead to the development of a mental health condition. On the other hand, if an individual is living with a mental health condition such as depression, they may experience a loss of appetite which can lead to sudden weight loss. If it is found that you are underweight because your diet is not providing you with enough calories, then this is something that can be rectified by adopting a balanced diet.

Seek the guidance of a qualified nutritionist if you are unsure of how to put on weight and may be concerned it could lead to excess calorie consumption as they would help you gain weight safely. Once you have reached your goal, they will help you to ensure you eat the right amount of food to meet your needs and remain within a healthy weight range. Your final programme should be achievable and realistic. It may include suggested supplements, physical activity recommendations, meal plans and a list of suitable foods. Regular consultations to monitor your progress will also provide opportunities to seek advice, support and motivation. These can help you focus on your goals so you do not stray from your programme and continue to improve your diet and fitness.

If an underweight person reaches a healthy weight and then begins to eat as they did before, they may experience weight loss once again. In order to avoid this, your nutritionist will work with you to ensure any changes made can be integrated into your daily lifestyle and are permanent. Once you have achieved a healthy weight, your nutritionist may suggest continuing with regular consultations until you feel confident and comfortable with continuing your new lifestyle and weight management independently.

Gaining weight can be herculean, and consistency is the key to long-term success. Whether you try to go under your set point (lose weight) or over it (gain weight), your body resists changes by regulating your hunger levels and metabolic rate. When you eat more calories and gain weight, you can expect your body to respond by reducing your appetite and boosting your metabolism. This is largely mediated by the brain, as well as weight regulating hormones like leptin. At the end of the day, changing your weight is a marathon, not a sprint. It can take a long time, and you need to be consistent if you want to succeed in the long run.