Not Weight, Not BMI: Scientists Say This Feeling Is An Indication Of Good Health

Body Mass Index (BMI) is a concept that has been around for a long time, dating back to the 19th century. However, it entered the mainstream in 1997 when the World Health Organization officially adopted it to define obesity, in light of the global epidemic. While it can be a reasonable guide for good health, BMI is far from perfect as a tool, and recent research suggests that an individual's energy levels may be a better indication of good health.

Weight has long been associated with good health, and many people nowadays are obsessed with reading on the scales. BMI calculations go alongside this, working out the proportion of weight to height and providing a value: 19–25 represents a healthy person, whereas over 25 is considered overweight, while 30 and above is labeled as obese. The issue with this system is that it doesn't take into account individual circumstances. Muscle is more dense than fat, meaning a very athletic person could weigh significantly more than a person of similar weight who does no exercise, meaning that their BMI values give more information about their body size or their likely health situation.

Scientists are now discovering that how a person feels and behaves in their day to day life can be a much better indicator of good or poor health than a number on a scale. When the body is working efficiently, going about your life should be effortless, and energy levels should remain steady as a result. In a study from Springer Nature in 2021, researchers found that older adults who self-reported consistently high energy levels also showed better physical and mental signs of good health.

Self-reported energy levels can provide a huge clue as to what is going on in the body, and whether a person is generally in good health. If you struggle to get through the day without multiple caffeine fixes to pick you up, it could be a sign that your body is struggling. Blood sugar crashes can be one common cause of low energy, and adding sugar to caffeinated drinks compounds the problem even further. Consistent energy levels are a good sign that your blood glucose is well managed, reducing the risk of insulin resistance, a key factor in Type 2 diabetes. Hormones such as estrogen and testosterone can also affect blood glucose levels, which is why energy levels can fluctuate during pregnancy and menopause.

Thyroid health also plays a huge role in energy levels, as your thyroid controls your metabolism. An underactive thyroid can leave you feeling sluggish as your metabolism slows down, while an overactive thyroid can be exhausting as your body is pushed to its limit. Sleep also plays a big part in day to day energy levels, and if your body is not getting enough rest, low energy can be the first symptom that your body needs to recharge. Chronic sleep deprivation can weaken your immune system and be a factor in serious disease, including hypertension and cognitive decline. It is also linked to mental health issues such as depression and anxiety.

If you feel that your energy levels are not where they used to be, there is no need to panic. Feeling tired temporarily is a natural part of human life, and if you have skipped a meal or had a poor night's sleep, it can likely be easily fixed. If the feeling of lethargy is longer term, however, it may be worth thinking about a potential cause.

Dehydration is a common culprit, so increasing your fluid intake throughout the day could make a difference in a short timeframe. Making sure you get a good night's rest and eating whole foods that keep blood sugar steady can also help your energy levels to stabilize over time. Gentle movement can help, too; even a short walk can make you feel better mentally and physically.

If you still struggle with energy levels, you may want to seek medical advice to rule out thyroid issues and hormonal changes, or any other underlying conditions. If you are used to stepping on the scales every day to see how healthy you are, it is time to switch your perspective and listen to what your body is subtly telling you.