There's no single "correct" weight for an age; it depends on height, body composition, sex, and build, but the Body Mass Index (BMI) range of 18.5-24.9 is a general healthy guideline for adults, while children use BMI-for-age charts. For adults, focus on BMI, but remember it doesn't differentiate muscle from fat, so consulting a doctor for a personalized ideal weight considering your unique body is best, as healthy choices matter more than a number.
For Infants < 12 months: Weight (kg) = (age in months + 9)/2 For Children aged 1-5 years: Weight (kg) = 2 x (age in years + 5) For Children aged 5-14 years: Weight (kg) = 4 x age in years.
Your most consistent and "true" weight is generally in the morning, after using the bathroom and before eating or drinking anything. This provides the most accurate baseline because your body has processed the previous day's food and fluids overnight, resulting in less fluctuation from digestion, water intake, and daily activities. Weighing at the same time, in the same minimal clothing, and under consistent conditions (like in the morning) helps track trends better than weighing at night or randomly.
If you're weighing yourself weekly, research shows that we're generally at our heaviest on a Sunday night and at our lightest on a Friday morning, so weighing in before breakfast on a Wednesday can give us the most accurate reading of our current weight [6].
The 3-3-3 rule for weight loss is a simple, habit-based method focusing on three key areas: 3 balanced meals a day, 3 bottles (or ~1.5L) of water by 3 PM, and 3 hours of physical activity per week, aiming for consistency over complex diets. It simplifies fat loss by establishing rhythm through consistent eating, adequate hydration to support metabolism, and regular movement, promoting sustainable health without intense calorie counting or restrictive rules, says Five Diamond Fitness and Wellness, Joon Medical Wellness & Aesthetics, and EatingWell.
Starting between ages 30 and 40, you may find losing weight and exercising more challenging. The exercise you do may not have the same effect as before. It's not necessarily a sign that something is wrong. This weight gain in middle age—known as “middle-age spread”—is a natural consequence of aging.
Sleep deprivation has long been linked to an increased risk of becoming overweight or obese. Researchers found that getting less than seven hours of sleep resulted in weight changes and may lead to weight gain, either by increasing food intake or decreasing energy burned.
The WHO weight-for-age charts show a pattern of slower weight gain after about 3 months of age since they are based on the weights of breastfed infants. When changing from the WHO-weight-for-age chart to the CDC weight-for-age chart, the weight-for-age percentiles may change to a lower percentile.
Your healthy weight range in Australia is generally a Body Mass Index (BMI) between 18.5 and 24.9, calculated from your height and weight, indicating a normal weight, but it's a guide, with ranges like 18.5-24.9 considered healthy, 25-29.9 overweight, and 30+ obese, with waist circumference also important for assessing risk, say NSW Health, Medibank, and Healthdirect, Australian Institute of Health and Welfare, Better Health Channel, and Cancer Australia.
Whether 80 kg is overweight for a woman depends entirely on her height, as weight is relative to body size; using Body Mass Index (BMI) or height charts shows that for shorter women (e.g., under 160cm/5'3"), 80kg is likely obese, while for taller women (e.g., over 175cm/5'9"), it might fall within the healthy to overweight range, but always use a calculator for accuracy as BMI doesn't account for muscle.
For adults ages 20 years and older, BMI incorporates weight and height, but it does not take age or sex into account. A woman tends to have more body fat than a man with the same BMI. Likewise, an older person tends to have more body fat than a younger person with an equal BMI.
At the same time, scientists uncovered another fact: men are also attracted to women with curves. This means that women with a BMI of 22.8 to 24.8 are the most appealing to men. This corresponds to a height of 170 cm and a weight of 70 kg.
The 3-3-3 rule for weight loss is a simple, habit-based method focusing on three key areas: 3 balanced meals a day, 3 bottles (or ~1.5L) of water by 3 PM, and 3 hours of physical activity per week, aiming for consistency over complex diets. It simplifies fat loss by establishing rhythm through consistent eating, adequate hydration to support metabolism, and regular movement, promoting sustainable health without intense calorie counting or restrictive rules, says Five Diamond Fitness and Wellness, Joon Medical Wellness & Aesthetics, and EatingWell.
Weight loss becomes more difficult after 45 due to changes in metabolism, hormone levels, and muscle mass. As we age, our body's ability to burn calories slows down, and hormonal shifts can lead to weight gain, especially around the abdomen.
Get active.
Strength training exercises are recommended at least twice a week. If you want to lose weight or meet specific fitness goals, you might need to exercise more. There is some evidence that high-intensity interval training (HIIT) can help reduce belly fat, as can strength training.
Although it's more common to skip breakfast or dinner, some people prefer to fast during the mid-day and skip lunch. There are not a lot of scientific studies on skipping lunch, but one research study revealed that skipping lunch and breakfast lowered total diet quality more than skipping dinner did [3].
Some of the ways she's lost weight include walking, eating more protein, and medication to help with how her body processes food. Clarkson started some of these changes to her diet and exercise routines when she moved to New York City, where she hosts "The Kelly Clarkson Show."
For example, the loss of water might make you feel a little lighter, but you're not getting rid of belly fat. It's just a loss of water. Try to choose an eating pattern that you can maintain over time. Even if you lose a few pounds on a 3-day cleanse or fast, these types of diets aren't sustainable over a long period.