According to this BMI calculator, for my age (63) and sex (female!) I am not overweight, as far as being healthy goes anyway! You might want to try it. It might make you re-evaluate your weight goals.
Here is my report:
This SBMI chart shows your BMI value and its age-dependent significance for the health. Your value is marked in the center of the highlighted area.
The calculation of the body mass index is based on a height of 5 feet 7 inches (170 cm) and a weight of 178 pounds (80.7 kilograms). New calculation?
BMI = 28
Your body mass index (BMI) is calculated as exactly 27.9 kilograms per square meter.
Your weight is at a level that, in our view, should be good for your health. We hold this statement contrary to the "overweight" classification of the WHO, read why ....
With a good balance of body fat and muscle mass, your blood pressure, cholesterol and blood sugar values are likely to remain at moderate levels. You would then seem to be well-protected against a heart attack, stroke or diabetes. This might be less so if your body fat is higher with a lower muscle mass, if you consume tobacco, other drugs or too much alcohol, lack physical activity or sleep, eat unhealthy food, or suffer from stress and other unhealthy life factors.
SBMI = 39/70
This assessment is based on the newly developed Smart Body Mass Index. Its ideal range is between 30/70 and 39/70.
Your Smart Body Mass Index (SBMI) is calculated as 39/70 or "39 points out of 70".
A stable weight at this level is fine, especially if you keep fit.
Your SBMI will decrease by about one point within ten years if you manage to keep your 178 pounds stable. This is due to the fact that the optimal, i.e. the "healthiest" BMI range increases with age, thus reaching higher BMI values.
This is no issue for you, luckily. But you may want to consider some suggestions that are well-advised, not only for weight reasons.
Your target weight of 164 pounds
You are already in your optimal weight range. Losing weight would add no benefit to your health.
Think over your diet. Eat a variety of foods that you like, optimally including five servings of fruit and/or vegetables a day. Avoid eating too sweet, too fat and too much.
Your current low-carb diet
With this diet you can achieve a fast weight loss by tricking your body. In the long run this may be unhealthy, as your body will try hard to compensate for the carbohydrate shortage by storing more fat. Beware of the yo-yo effect. If you want to stop dieting, do it step by step.
Do physical exercise at least for half an hour daily at moderate to vigorous intensity. Walking or cycling may be better for your joints than jogging.
Important to know
This feedback can only be based on the inevitably limited extent of the data that you have entered here. This data has been evaluated by comparing it with the results of the most comprehensive study published so far on the BMI and its associated health risks.
The results and comments above can only give you an estimate that applies to all women at 63 years of age with a body mass index of 28, as a statistical group. They are non-personal. They should never replace medical advice.