Weight went up and my check-up got worse. Where to start?

When your weight has gone up and several values on your health check look worse at the same time, start with three steps. First, have a doctor read all your results together and tell you which one to look at first. Second, measure your waist as well as your weight: a WHO expert consultation found that in different Asian populations health risks were observed from a BMI of 22 to 25 kg/m², and England's NHS advises keeping your waist under half your height. Third, choose a few habits to change and aim, to begin with, to stop your weight rising further.

Why do several values change at the same time?

A health check reads them as a set

A health check measures several things at one visit. The NHS Health Check in England, for example, includes height and weight, waist, a blood pressure test and a cholesterol test, may check blood sugar, and asks about smoking, alcohol, physical activity and family history. The results are then discussed together, along with advice on diet, exercise, weight, salt and alcohol. Thai health check packages from workplaces and hospitals often include many of the same items.

The same habits sit behind several numbers

Weight, blood fats, blood pressure and blood sugar are separate values, but the everyday habits that affect them overlap: what and how much you eat and drink, how much you move, alcohol, smoking and sleep. So these habits are worth looking at together. Decide with your doctor which value to work on first.

How common is weight gain among Thai adults?

Gaining weight through adulthood is very common in Thailand, and three sets of Thai data show it from different angles.

Adults followed over 8 years

A study by Yiengprugsawan and colleagues followed 27,003 Thai adults aged 25 to 40 in the Thai Cohort Study and compared their weight in 2005 and 2013.

The weights were reported by the participants themselves, so they are less exact than measured weights.

The national survey, 2004 and 2019–2020

Thailand's National Health Examination Survey measures adults about every 5 years, between about 19,000 and 38,000 people in each round (19,062 in 2019–2020). In the figures reported by Aekplakorn and colleagues, the BMI of Thai adults aged 20 and over shifted upwards:

These figures come from the table describing each round's participants, whose age mix differed: for example, adults aged 20 to 39 made up 50% in 2004 and 32.5% in 2019–2020, so the figures are not adjusted for age.

Young men, too

A study of 54,622 new military conscripts, with an average age of about 21, found that average BMI rose from 21.7 in 2009 to 22.5 in 2024, and the share with a BMI of 25 or more rose from 12.5% to 22.6%. So weight gain is not only a middle-age change.

Which numbers should I look at for my weight?

BMI, with Asian cut-offs

BMI is your weight in kilograms divided by your height in metres squared. The WHO expert consultation found that in different Asian populations, the BMI at which health risks were observed ranged from 22 to 25 kg/m², lower than the usual international cut-off of 25. It kept the international categories but identified extra points for public health action:

The NHS BMI calculator also notes that people from an Asian background have a higher chance of health problems at a lower BMI, and that BMI cannot tell the difference between muscle and fat.

Waist size

Because BMI cannot tell muscle from fat, measure your waist too. The NHS advises keeping your waist size to less than half your height. If you are 160 cm tall, that means a waist under 80 cm; at 175 cm, under 87.5 cm. Measure in the same way and at the same time of day each time.

Where should I start?

Step 1: let the doctor set the order

Bring this year's and earlier results. Ask which value matters most for you, whether anything needs checking again soon, and what weight or waist goal is realistic. If you started any new regular medicine around the time your weight went up, mention it.

Step 2: look at what changed

Think back to when the weight began to go up. Common changes are a new job with more sitting, more meals out or delivered, more sweet drinks or snacks, more drinking with colleagues, and shorter sleep. The habits that changed are usually the best place to start.

Step 3: choose a few habits

Thai examples: swap sweetened iced tea or coffee for less-sweet or unsweetened versions, have fruit instead of a sweet snack in the afternoon, add a vegetable dish to rice-and-one-dish meals, and walk part of the way to work. For starting to move when you sit all day, see I sit at work all day and barely exercise. Where do I start?

Step 4: aim for steady, not fast

The US CDC notes that fad diets promise to work quickly but limit your nutrition, can be unhealthy and tend to fail in the long run. A first goal of keeping your weight from rising further is easier to reach and to keep. Weigh yourself about once a week and measure your waist about once a month, at the same time of day.

What should I prepare before the next health check?

Keep your records

Keep every result, and note your weight and waist between checks. The doctor can see far more from a trend than from one year's numbers. For preparing in the weeks before a check, see My health check is coming up again. What should I change?

When to go back sooner

See a doctor sooner, rather than waiting for the next check, if your weight changes quickly without a change in eating or activity, or if you notice other changes in how you feel. Keep taking regular medicines as prescribed and do not stop them on your own; if you take regular medicines, or are pregnant or breastfeeding, talk to a doctor or pharmacist before making big changes to how you eat.

For the blood fat section of your results, see I'm in my early 30s. Should I start watching my blood fats?