Answering clients’ fat loss questions

By explaining fat loss and body composition basics, and perfecting the measuring techniques involved, you can empower your client and define clear outcomes, says Bill Sukala.

Personal trainers are continually asked for advice on fat loss by clients and prospective clients. While it isn’t possible to condense the wealth of detailed knowledge we gain from training courses and ongoing education into easily understandable soundbites, it is possible to give brief overviews of certain areas in reply to some of the most commonly asked questions.

Is all fat bad?

Let’s face it: body fat has a bad reputation. Despite all the bad publicity, fat is actually a physiologically important substance that serves a number of valuable purposes in the body.

  • Pads our internal organs
  • Aids in digestion of vitamins A, D, E, and K (stored in fat tissue and the liver)
  • Used in making bile acids
  • Forms part of the cell wall structure and assists with cellular functions
  • Helps maintain body temperature and protect against cold
  • Protects us against starvation.

So this ‘spare tyre’ is actually normal and healthy?

Remind clients that, unfortunately, too much of a good thing is not always a good thing. It is well known that excess body fat poses a health risk, but as our scientific understanding of fat improves, we now realise it’s the regional location of fat on the body – particularly around the mid-section – that makes the difference between healthy or harmful. Unlike pinchable fat just beneath the skin surface, deep belly fat – or visceral fat in technical terms – penetrates well into the abdominal cavity and wraps itself around vital organs. Visceral fat is very metabolically active and secretes harmful chemicals called adipocytokines into the bloodstream. Adipocytokines have been shown to hasten the development of diabetes, cardiovascular disease, high blood pressure, high cholesterol and some types of cancers.

How do I get rid of belly fat?

First, all the infomercial ab gimmicks that promise to strip fat off your abdominals are complete rubbish and will only leave you lighter in the wallet. Spot reduction, i.e., selectively targeting fat from your abs, is a myth that refuses to die. The secret to losing belly fat is that there is no secret! The best available evidence using highly sensitive measures of visceral fat, i.e., CT (computed tomography) or MRI (magnetic resonance imaging) scans shows that reduced kilojoule intake, moderate exercise, or a combination of both effectively reduce abdominal fat stores.

However, certain factors do appear to stoke the fat-burning furnace. A study conducted at Duke University in the US found that exercising at a higher intensity enhanced visceral fat loss. Another study conducted in post-menopausal women with type 2 diabetes showed that adding moderate-intensity aerobic exercise to a reduced calorie diet resulted in a 13 per cent reduction in visceral fat tissue compared to a 7.5 per cent reduction in study subjects who only partook in the reduced calorie diet. Resistance training, which is excellent for bone health and muscle tone, has also been shown to reduce abdominal fat.

How can I tell how much fat I’m losing?

To accurately gauge fat loss, trainers need to be able to take accurate measurements. It is incredible how many clients fixate on their percentage body fat, regardless of whether the numbers are accurate or reliable! There are a number of ways to estimate body composition (amount of muscle, fat, body water, and a percentage of body fat). The most reliable methods, however, are found in exercise physiology labs or hospitals (underwater weighing, CT scans, dual energy x-ray absorptiometry (DEXA)) and are not easily accessible to fitness professionals.

Most trainers use quick field measures such as skinfold calipers and bioelectrical impedance analysis (BIA) to make a best ‘guesstimate’ of body composition, but increasing associations between levels of belly fat and health risks mean that the trusty tape measure is also making a resurgence. Let’s take a closer look at these three body composition assessment methods;

  • Skinfold calipers: This method entails pinching the fat at various sites on the body using precise anatomical landmarks and measuring the skinfold thickness (in millimetres). The sum of skinfolds from all sites is then entered into a formula to calculate an estimate of body fat percentage.
  • BIA: The bioelectrical impedance analysis device sends a small but harmless electrical impulse through the body which measures internal resistance to the current and provides an estimate of total body water. Using this information the machine calculates an estimate of body fat and lean (muscle) mass. In general, the leaner you are, the more body water you have, and consequently, the more easily the current passes through. More body fat provides more resistance (impedance) to the current and therefore registers a higher percentage of body fat. BIA must NOT be used on clients with pacemakers, implanted cardioverting devices (ICDs) or anything else that might interact with BIA.
  • Waist circumference: Simple though it may be, a basic tape measure can tell quite a story. This is not a body composition method in the strict sense of the word, but it does give an idea of the regional distribution of body fat and the potential for future health risks.
Body fat ranges





< 17%

< 12%


17 to 28%

12 to 21%

Moderately overweight

28 to 33%

21 to 26%


> 33%

> 26%

Waist circumference and health risk




Low risk



Increased  risk

82 to 87

94 to 101

High risk



*‘norm’ values vary, but the cutoffs shown here provide good pragmatic values

As trainers, we should be conscious that there is a margin of error associated with body composition assessment techniques. If you are relatively inexperienced at measuring body fat with calipers, be careful not to grab both muscle and fat, as this will give a higher reading. Pinching the skin at the wrong sites can also skew the results since the method is based on standardised sites.

BIA is susceptible to the client’s hydration status, which can be influenced by such things as fluid intake, diuretic medications, and menstruation. To help mimimise the potential for error, measure the client at the same time on a different day and under similar circumstances. BIS is also more likely to give inaccurate results in very obese individuals.

For circumference measures, make sure the tape measure is level and is applied to either bare skin or a thin shirt. You should practice your measuring technique to ensure you are measuring at the exact same location each time.

When aiming for fat loss, clients often have questions about ‘the numbers’ involved. This information is useful to both you and your client, providing key performance indicators (KPIs) which can be used to measure progress. By explaining these body composition basics, and perfecting your grasp of the measuring techniques, you can empower your client and define clear outcomes.


Bill Sukala, PhD is a Sydney-based clinical exercise physiologist specialising in clients with cardiac and metabolic concerns. He holds a PhD in Exercise and Science with a research focus in diabetes and obesity, a Masters degree in Exercise Physiology with specialisation in cardiology, and a Bachelors degree in Nutrition. An international speaker who has delivered keynotes, seminars, and workshops across five continents, Bill is frequently quoted on health topics by major media outlets around the world.