When someone goes down or up heavyamount fat cells in your body they neither increase nor decrease. We have to think of it as a balloon: fat cells expand or contract, and in each person this happens in a different way, which means that each one stores different fat stores safely.

The usual trajectory is that most people will gain weight as they get older until they reach their age 60 years and then start losing weight. However, the “ideal” weight depends entirely on who you are, as the amount of fat you can safely store is individual. There will be bigger people who are metabolically fit and skinny people who have diabetes.

I will define someone fat like someone who carries too much fat, so it starts to affect his health. For example, in my case, as an East Asian, I can’t have a BMI (Body Mass Index) too big before i increase the risk of diseases like type 2 diabetes, because we have a lower ability to transport fat safely.

BMI is very useful for observing population trends producel, because it is easy to measure and requires only two accurate data: height and weight. But individual levelThis calculation is not always useful for predicting health status because it does not take into account genetic and ethnic differences in the ability to store and metabolize fat. You can be a rugby player, or be the same size as a rugby player without exercising and being fat, but have the same BMI.

In short, the main problem with BMI is that it doesn’t take into account the amount of fat or muscle you have because where adipose tissue is located also affects your state of health.

In a recent report with Guardian, I’m talking about considering the type of food we eat, not just looking at the calorie content. One might aim to eat 800 calories a day, but how much energy your body absorbs will depend on whether you eat sugar, celery, or steak.

It really pisses me off when weight loss gurus say things like, “Oh, just replace the candy with a banana.” Saying that is ridiculous, because sometimes life needs bananas, and sometimes life needs candy.

As is known, the inches around the stomach is more dangerous than the increase in total weight, because visceral fat accumulates around the internal organs and is associated with an increase risk of cardiovascular disease and cancer.

Also, it should be remembered that exercise alone is not effective for weight loss. In principle, losing weight through exercise is possible: Tour de France cyclists eat at least 5,000 calories a day and keep the weight off for three weeks of the race. The problem is that most of us mere mortals don’t exercise closely enough for this to be effective. However, it is useful to maintain the weight once you have achieved it. So I stay active cycling and running, to stay fit, but also to keep my weight down.

Middle-aged people tend to be less active because they are mostly sitting doing their jobs, compounded by the fact that, having increased their purchasing power, they tend to eat the richer diets they can afford on average.

Instead of chasing a specific number on balance between the ages of 40 and 50, the ideal is focus maintain muscle mass and maintain a healthy weight-to-height ratio (BMI).

The amount of muscle you carry is the most important piece of information as you age. The more muscle you have as you get older, the healthier you will be. You metabolism it remains stable for a very long time, such as 60 years of age, before starting to decline.

Why do we lose muscle after 50? As they get older, most reduce their physical activity and this pays off muscle lossas I recently explained in an interview at Telegraph. So, because muscle has a higher metabolic rate in your body, a person can weigh the same as when they were young, but if their body composition contains more fat than muscle, the basal metabolic rate — the basic number of calories each individual needs someone to live on—will be less.

A suggested physical routine should include: exercises that use your own body weight, such as push-ups, resistance bands and/or lifting weights. Also count heavy objects around the house or shopping bags, all activities add up to achieve the goal of good resistance training.

At age 60, it may not be too late to lose weight, as it increases your ability to live a healthier longer life.

In this decade, it’s advisable to keep your weight within a healthy BMI range, which will help fight off a slow metabolism. If you’re gaining weight, it’s time to incorporate a a diet high in protein and low in sugar, refined foods and refined carbohydrateswhich includes white bread, pasta, cakes, and tarts.

Start by developing moderate aerobic exercise, such as brisk walking, working your way up to the World Health Organization (WHO) recommendation of 150 minutes per week. You may still be working towards retirement so there are opportunities to extend your life and I think people are thinking about that.

As people reach their 70s and 80s, obesity is generally less of a problem because weight is lost fairly quickly, either through decreased muscle mass or decreased appetite.

However, contrary to what is commonly thought, Strength training more important than ever in the 70s and 80s, like Muscle helps maintain heart health and bone density.

If you survive into the mid-70s, I think you have to live your life the way you want to, not about how much butter you put on your toast.

It doesn’t matter how old you are, you should always do resistance training. Even the simplest strengthening exercises, such as sit in a chair and raise your calvescan make a difference in the maintenance of muscle mass.

I think people underestimate how much training impacts your life and that really matters as you get older. It’s never too late to get fit.

*Dr Giles Yeo is Professor of Molecular Neuroendocrinology at the University of Cambridge, UK

*Material taken from the book Why Calories Don’t Count and Gene Eating, by dr. Giles Yeo

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