Unveiling misconceptions: What physios need to know about obesity

I am certain that all clinical physios are aware of the worldwide epidemics of obesity and the resultant mobility limitations that affect our patients.

However, I think many of them still believe in misconceptions about excess body weight and its impacts on the musculoskeletal (MSK) system. Because of that, their clinical practice underpins erroneous concepts and ineffective strategies.

In this blog, I explain three principles you should know about this topic to avoid these mistakes.

#1 Obesity is a complex and multifactorial chronic condition.

In other words, obesity is not a personal problem of lacking willpower.

The excess of body fat is a consequence of an intricate net of environmental and individual factors. These factors include social, economic, and cultural conditions concerning biological aspects, both physical and psychological. Public health and clinical programs for obesity must consider all these factors.

In addition, obesity is considered a chronic disease, not only a risk factor for health problems. In this way, prevention and treatment of obesity and comorbidities must emphasise specific long-term strategies and specialised professional monitoring.

#2 The impact of obesity on the MSK system is beyond overloading joints.

Besides the increased mechanical load on weight-bearing structures, body fat exerts systemic effects on the whole body. The adipose tissue causes harmful effects in many organs and tissues through metabolic mechanisms linked to the immune and endocrine systems.

Because of these remote effects, obesity is associated with osteoarthritis, rheumatoid arthritis, fibromyalgia, low back pain, osteoporosis, and chronic pain in various joints.

The common pathways linking body fat and the MSK system include three main mechanisms:

• Inflammation: Adipose cells, particularly those from visceral adipose tissue, produce several pro-inflammatory cytokines like Tumor Necrosis Factor-alpha (TNF-alpha) and IL-6 (interleukin-6). These cytokines contribute to a systemic, chronic low-grade inflammation that is associated with many chronic diseases, like cardiovascular, musculoskeletal, neurological, and degenerative conditions.
• Bone health: The adipose tissue regulates the levels of specific cytokines called adipokines, like leptin and adiponectin. The adipokines can lead to imbalances in bone metabolism and have negative impacts on musculoskeletal health. Reduced levels of physical activity, hormonal imbalances, and vitamin D deficiency are also common among patients with obesity, increasing the risk of osteoporosis, frailty fractures, and MSK disorders.
• Metabolic changes: Obesity is associated with metabolic dysfunctions like insulin resistance and alterations in glucose metabolism. These metabolic changes can negatively impact the health of bones and joints, potentially leading to MSK disorders.

These three mechanisms can be exacerbated by the physiological changes of the aging process, aggravating or increasing the risk of geriatric syndromes like sarcopenia and frailty. Contrary to common beliefs, it is not only the malnutrition and low weight that are associated with these conditions among older people.

#3 Exercises for patients with obesity should not focus on losing weight.

I’m not saying that you should not pursue reducing body weight as a clinical objective. However, focusing exclusively on this outcome can be frustrating and counterproductive. Instead, it is necessary to reshape our approach towards patients with obesity, to prioritise the overall MSK system and go beyond the numbers on a weighing scale.

As physiotherapists, function and quality of life must be our main targets, and physical exercises are the most effective tool to achieve them. Our therapeutic strategies for patients with obesity should not be focused exclusively on losing weight. It is essential to reinforce MSK health including muscle and bone mass, in quantity and quality. Therefore, aerobic exercises must be combined with resistance exercises. If you’d like to learn more about prescribing physical activity for the management of chronic disease, watch Dr Jane Thornton’s Masterclass HERE.

Resistance training

This has multiple benefits for health and quality of life. Resistance exercises are an essential component of physical activity regimens, being widely recommended for all age groups and many health conditions. If you want to know more about exercising and health, check the detailed prescriptions in the World Health Organisation’s (WHO) Global Recommendations on Physical Activity for Health (1).

In terms of prevention and treatment for obesity, resistance training contributes to improvements in body composition and supports weight management. Resistance exercises can help to reduce fat mass, increase lean mass and rebalance the metabolic changes exacerbated by the excess of body fat.

In terms of MSK health, resistance training contributes to improvements in muscle functioning and bone metabolism, ameliorates symptoms of pain and stiffness, and mitigates the impact of mobility limitations associated with obesity and MSK disorders.

These effects result from an interplay of mechanisms, like:

• Elevated resting metabolic rate: The development of lean muscle mass elevates the basal metabolic rate and helps to burn more calories during periods of rest.
• Post-exercise caloric expenditure: Resistance exercises creates an elevated post-exercise caloric expenditure, known as excess post-exercise oxygen consumption. This results in additional calorie expenditure after the exercises.
• Enhanced fat oxidation: Resistance exercises induce a shift in the utilisation of fat for energy and improvements in insulin sensitivity and glucose metabolism.
• Appetite regulation: Resistance training can help to regulate appetite, influencing hormones like leptin and ghrelin.
• Mental health and well-being: Engaging in resistance training can have positive psychological effects, reducing the symptoms of depression and anxiety.
• Anti-inflammation effects: During resistance exercises, contracting muscle cells can liberate anti-inflammatory cytokines like Interleukin-10 (IL-10) and Brain-Derived Neurotrophic Factor (BDNF), produce antagonists to pro-inflammatory cytokines IL-1, IL-6 and TNF-alpha, and also produce myokines with beneficial effects over adipose and muscle tissues, like irisin, myostatin and Factor Growth Factor 21 (FGF21).
• Functional capacity: Resistance exercises can enhance physical function and functional capacity for daily activities, improving the muscle performance in strength, power and endurance. Because of that, resistance exercises are included in many preventive and therapeutic strategies for MSK disorders.
• Healthy aging: Resistance training contributes to counteract the effects of sarcopenia and osteopenia during the aging process. Resistance exercises also collaborate to prevent common adverse effects among older people, like falls and fractures. Losing weight without preserving muscle mass and function is particularly unfavorable for older people, resistance training ensures a safer reduction in weight as people age.

Wrapping up

It is essential to recognise the impacts of excessive body weight on the MSK system, besides the mechanical strain on joints. Clinicians should consider the complex net of metabolic, inflammatory, and systemic effects of the adipose tissue when prescribing exercises for patients with obesity. Recognising these effects underscores the importance of comprehensive interventions targeting both the MSK and the general health for these patients.

To learn more about how the experts prescribe physical activity for chronic conditions, watch Dr Jane Thornton’s Masterclass HERE.