Cut the Waist

Cut the Waist

Illustrative photo for 'Cut the Waist'
A modest reduction in waist circumference can have significant long term health benefits

High-risk fat is the first to go

The impact of moderate weight loss

The phenomenon whereby fat in high risk sites is preferentially lost is illustrated by the following examples:

Liver fat

A loss of 8% body weight over 7 weeks was associated with an 81% decrease in liver fat in one study1. During weight loss, there is a tight relationship between liver volume and liver fat content: it appears that liver fat is mobilised more rapidly than visceral fat or subcutaneous fat2.

Visceral fat

Recently published meta-analysis of 61 studies confirms that modest weight loss generates preferential mobilisation of visceral adipose tissue. The authors conclude that this observation may help to explain the metabolic benefits of modest weight loss3. Very low calorie diets and also one of the newer diabetes medications, the GLP-1 agonist Liraglutide, have been show to facilitate preferential mobilisation of visceral fat.

Illustration of the impact of moderate weight loss

Monitoring weight loss progress and health improvement

Monitoring health improvement by change in body shape

Measuring waist reduction as well as weight reduction is important as it provides encouragement that high-risk body fat is being lost around the abdomen. It is helpful to monitor progress using serial waist circumference measurement every month or so in addition to weighing every 1-2 weeks. A waist circumference reduction of 1cm is equivalent to losing 1kg (2lb) of body fat.

If you plan to embark upon a programme of graded physical activity as recommended as part of your weight loss effort, monitoring progress via serial waist circumference measurement may be of particular benefit.

Do not worry about relatively slow weight loss when embarking upon a programme of increasing activity, as physical activity should bring about an increase in muscle mass. This increase in "engine size", through an increase in muscle mass as a result of increasing activity, is extremely helpful in sustaining a healthier weight in the longer term. However, the increase in muscle weight can sometimes mask just how much loss of body fat has taken place.

In these circumstances, do not worry about apparent lack of weight loss as long as your body shape is changing and waist circumference reduction is taking place.

If your body shape is changing and waist reduction is occurring, you are making progress.

Illustration of an increase in engine size (muscle mass) through regular activity

An increase in engine size (muscle mass) through regular activity is the key to sustaining weight loss in the longer term. It is easy to see why the Aston Martin engine would burn more fuel than the Mini engine.

Starting a graded activity programme will help to upgrade your engine size and help maintain weight loss in the long term.

Monitoring health improvement through risk factors

As liver fat and visceral fat are preferentially mobilised with weight loss, markers of liver fat accumulation (ALT) and visceral fat (fasting triglycerides) improve within a short period (a few weeks to a few months) following modest weight loss.

Blood pressure reduction can also occur within a relatively short time frame following weight loss.

Improvements in fasting lipid profile - specifically a rise in protective HDL cholesterol - may take 6 to 12 months.

Similarly, improvement in medium term blood glucose control as measured by HbA1c may be seen over a 6 to 12 month period following successful weight loss achieved via lifestyle measures or pharmacotherapy.

However, significant weight loss as a result of weight loss surgery (bariatric surgery) can be associated with more rapid improvements, particularly in blood glucose control in people with type 2 diabetes.

References

1. Petersen KF, Dufour S, Befroy D, Lehrke M, Hendler RE, Schulman GI Reversal of non-alcoholic hepatic steatosis, hepatic insulin resistance, and hyperglycaemia by moderate weight reduction in patients with type 2 diabetes. Diabetes 2005; 54: 603-608

2. Colles SL, Dixon JB, Marks P, Strauss BJ, O'Brien PE. Pre-operative weight loss with a very low energy diet: quantification of changes in liver and abdominal fat by serial imaging. Am J Clin Nutr 2006; 84: 304-311

3. Chaston TB, Dixon JB. Factors associated with percent change in visceral versus subcutaneous abdominal fat during weight loss: findings from a systematic review. Int J Obes 2008; 32: 691-628