Weight Loss in Middle-Aged Adults and the Elderly

Resident Dietitian, Rick-Lee Driver sat down with us and explained how weight loss strategies vary among middle-aged and elderly populations.

Introduction to Weight Loss

Obesity remains the most predominant and misunderstood chronic disease condition within our current society. The first line strategy in the management of overweight and obesity is diet and lifestyle modification. However, as our understanding of this chronic disease increases, the question arises;

Are we missing basic physiological factors contributing to the condition?

Sarcopenia is the involuntary loss of muscle mass, strength and function. After the age of 30, the average person will lose 3-8% of their lean muscle mass per decade, increasing upwards to 15% in persons 65 years or older.

An individual’s Basal Metabolic Rate (BMR) can also decrease at a rate of 1-2% per decade after the age of 20. Which further contributes to the loss of lean muscle mass. This raises the question;

When exploring weight-loss strategies in overweight or obese adults over the age of 30 years, is sarcopenia and unnoticed factor inhibiting long term weight loss and maintenance?

And if so, how is long term weight loss achieved without increasing the rate of lean muscle mass and BMR decline?

The factors that should be considered when discussing weight-loss strategies in middle-aged or older adults are detailed below.

Energy

Weight loss strategies can vary significantly from oral energy restriction to behavioural change and counselling strategies. A 500-600kcal/d oral energy restriction will support a gradual weight loss (0.5kg per week) in overweight and obese adults whereas Low Energy Diets (1000-1500kcal/d).

Very Low Energy Diets (<1000kcal/d) have been shown to result in more significant weight loss (1kg per week).

Weight regain after weight loss is a common occurrence, increasing body weight by 5% with every diet cycle. This weight gain is attributed to loss of lean muscle mass and decreases in metabolic rates.

Studies show that approximately 25% of total weight loss with low energy diets is associated with loss of lean muscle mass. Very low energy diets resulting in greater lean muscle mass loss. Despite the risk of lean muscle mass loss, Low Energy Diets have an array of health improvements ranging from:

• Insulin resistance
• Diabetes
• Fatty liver
• Blood pressure
• Weight loss

Nutrition is an essential factor in mitigating lean muscle mass loss whilst on a low energy diet, particularly for those middle-aged and older adults.

An Accredited Practicing Dietitian can assess an individual’s suitability for these programs and provide dietary or supplement guidance to protect nutritional adequacy, reduce the risk of lean muscle mass loss during oral restriction and prevent weight regain.

Protein

Dietary protein is widely recognised as the macronutrient most beneficial in lean muscle mass retention. The current recommended daily protein intake for adults between the ages of 31-50 year range between 0.75g-0.84g per kilogram per day, increasing to 0.94-1.07g per kilogram per day for those over the age of 70 years.

These recommendations are estimated to account for the amount of daily protein required to maintain lean muscle mass. However, there is increasing evidence that eating beyond this recommendation is beneficial in sarcopenic individuals.

Increasing dietary protein to between 1.7–2.3 g/kg/day has been shown to result in improvements in lean muscle mass retention paired with an oral energy restriction in these groups. Chronically high protein intakes (>3.0g/kg/d) can have adverse effects on bone metabolism, heart disease and liver function and are not recommended.

Protein supplementation should be patient-tailored and past medical history or susceptibility to renal or bone metabolism abnormalities should be considered by an Accredited Practicing Dietitian.

Resistance Movement

Exercise is traditionally divided into two categories resistance and aerobic (endurance). Resistance exercise is most recognised for its role in muscle hypertrophy (growth) and increased strength.

Including resistance exercise whilst in an energy-restricted state has been shown to reduce the proportion of lean muscle mass loss from 25% to approximately 17%. Increased intensity and volume further contribute to retention.

Studies have shown that whilst weight loss through oral energy restriction alone is similar to weight loss with resistance exercise, interventions including resistance exercise demonstrated near-complete retention of lean muscle mass.

Exercise compliance on an energy-restricted diet can vary, however, further highlighting the importance of engaging with a multidisciplinary team experienced in achieving weight goals.

Summary

Dietary restriction independently will likely result in a decrease in lean muscle mass, exacerbating the risk or progression of Sarcopenia in middle-aged and elderly adults.

Reduced lean muscle mass will negatively impact basal metabolic rates and likely result in weight regain following the weight loss attempt. Protein intake whilst on an energy-restricted diet will help maintain lean muscle mass in combination with the resistance movement.

Engaging with a specialised Medical and Allied Health team will increase the success of long term weight loss, muscle retention and basal metabolic rate in middle-aged and elderly patients.

The potential risks and benefits of weight loss should be considered on an individual basis when considering the implementation of an energy-restricted diet for elderly persons.

If you’re feeling that you may require more support and guidance with your weight loss journey, contact us today and speak with our friendly admin team.

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Written By Dietitian, Ricki-Lee Driver