Being overweight may have a protective effect on older people, study finds

The body mass index (BMI) is the formula that many doctors, and many patients, use to measure the state of health, although many health professionals have questioned it for some time. Only weight and height in meters squared are used to calculate it, without taking into account the sex, age or physical activity carried out by the person. Anything outside the range considered normal by this scale (18.5 and 24.9) is considered unhealthy. Now, research from the British Dietetic Association (BDA) has found that, in older people, being within what is considered overweight (between 25 and 30) can have protective effects on their health.

Mary Hickson, co-author of the review of studies published last November, explains that, compared to younger age groups, people between 70 and 80 years old have a lower risk of death if they are slightly overweight. “There are other factors, like exercise, that are more important,” she says. This fact is known as the obesity paradox, which maintains that being overweight may be related to greater survival in certain groups of people.

The BMI recommendations are based on the results in young people, explains Naiara Fernández, coordinator of the nutrition group of the Spanish Society of Geriatrics and Gerontology (SEGG). A body mass index between 28 and 30, which can indicate grade 1 obesity in younger people, would be considered normal in terms of weight in older people, so it would not really be overweight, details the geriatrician.

Having BMI as the only indicator of excess weight is a mistake, says Jesús Román, president of the scientific committee of the Spanish Society of Dietetics and Food Sciences (SEDCA). The elderly may be within the normal range, but have almost no muscle mass, which harms their health, adds the nutritionist. They may even suffer from sarcopenic obesity, which occurs when body fat mass increases and muscle decreases, something very common in this age group. Therefore, the important thing is to carry out a comprehensive geriatric assessment, adds Fernández.

The problem with an older person following a restrictive diet to lose weight is that, in addition to fat, their muscles can also decrease. This can lead to it being more fragile, moving worse and being more prone to falling and injuring itself, explains Román. Being slightly overweight can have a “cushioning” function to prevent the bone from breaking if you fall, he adds. If you need to lose weight, it is appropriate to increase energy expenditure with exercise instead of reducing daily calories, indicates Jose Antonio Serra, head of geriatrics at the Gregorio Marañón hospital in Madrid.

Fernández explains that the main thing is for the elderly to remain autonomous and independent and for that they need muscles in good condition that allows them to lead a quality life. Therefore, regardless of BMI, the expert only recommends weight loss in cases in which pathologies such as hip or knee osteoarthritis limit mobility. “We must focus on the terms that make them gain health,” says the geriatrician. Additionally, low weight and malnutrition increase the incidence of osteoporosis.

It is important to know the dietary habits of older people, explains Serra, from Gregorio Marañón. “There are times when they have excess weight because they eat poorly, not because they eat a lot.” Many times they do not have healthy eating habits because they live alone, they have difficulty going shopping, they may have financial difficulties that prevent them from accessing quality protein, or they do not feel like cooking because they have no one to share it with. These situations are a risk because they can make them choose to consume processed products that will have a negative impact on their health, says Fernández.

It is also important to assess each person's fat distribution. If it is distributed evenly throughout the body, it is “much less harmful” than if it accumulates in the abdomen, says Serra. In the second case, there is a greater risk of suffering from metabolic syndrome, diabetes and heart disease, continues the geriatrician.

Involuntary weight loss

In the BDA research, the authors show their concern about the involuntary weight loss of older people, which they find more worrying than being overweight. Hickson, co-author of the work, explains that it can be due to many causes such as social isolation, chronic diseases, a process of grief or depression, oral health or taking drugs that affect appetite, digestion or the absorption of nutrients. , among others. “Detecting malnutrition, identifying when it is a risk and evaluating possible causes are crucial to planning appropriate care,” she emphasizes.

To confront this situation, Fernández explains, a “very multidisciplinary” plan is needed that includes a support figure, a physical exercise intervention, and the removal or replacement of drugs that cause adverse effects. You must also assess whether you need nutritional recommendations or dietary supplements.

A study published last April in the journal Nutrients He also advocated better survival for overweight or obese older people. Its authors consider that BMI is not the best criterion because it does not provide information about body composition and is less correlated with body mass percentage. The research found that older people who are moderately overweight and have chronic diseases or acute medical events have better survival. Furthermore, the authors hypothesize that, in the elderly, a high BMI could also reflect better nutritional status and adequate muscle reserves.

Hickson believes it is time to “review the evidence to see if the WHO can make recommendations for all populations.” The author of the BDA research recommends other changes, such as strength training to strengthen muscles instead of guidelines for older people to lose weight. When measuring the weight of an elderly person, the nutritional situation must be assessed. If you are obese, you also have to look at the impact they have on your health, for example looking at your glycemic control, says Fernández, from the SEGG. “It is not the weight or the restrictive diet, what we have to look for is functionality and promoting physical exercise,” she asserts.

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