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It’s time to say the F-word!

I usually start my Bodyscan consultations with the question “What brings you to Bodyscan? Why do you want to have a DEXA scan?”, to which the answer is usually “I want to lose body fat and check my progress until I reach my target.”

Fair enough – DEXA is highly consistent between scans, meaning it can reliably measure even small changes in body fat. Consistency – as this DEXA video explains – is arguably more important than accuracy (at which DEXA also wins, which is why it’s regarded as the ‘gold standard’ in body composition measurement).

However, when I ask if the client has some sort of plan to achieve the fat-loss, the client invariably says they are going to do one or more of the following:

  • Join or get back to the gym
  • Start running
  • Walk to work
  • Do more exercise
  • Sign up with a personal trainer
  • Follow an exercise programme they found online
  • Increase cardio
  • Do the ‘4-Hour Body’ (read this before you do!)

After which, I usually say the F-word out loud.


​Because in perhaps 95% of cases, the client never mentions food at all.

And that’s not a good start because, whatever anyone tries to tell you, exercise and activity is NOT the best strategy for shedding body fat. It certainly contributes and has a significant cumulative effect over time, and it’s something we should all do more of. Certainly, we were not made to sit at desks or in cars for most of our waking hours, and being sedentary is a huge contributor to the woeful statistics on obesity and its related diseases.

Visceral fat (internal fat that builds up around the organs) increases almost inexorably with age but is much higher in individuals who are sedentary and do no exercise. Because internal fat is metabolically active it responds directly to increased activity. At Bodyscan we have seen DEXA scans record big reductions (50%) in visceral fat in response to significantly increased levels of activity.

Further, exercise has been shown to improve mood and sleep, reduce anxiety, keep us mobile for longer and enhance overall wellbeing. Plus, of course, by doing exercise, we become fitter, stronger, more flexible and burn more calories, which can contribute to a calorie (energy) deficit over time. A calorie deficit occurs when we consume fewer calories than we expend. A sustained calorie deficit is essential for losing body fat.

But as a PRIMARY strategy for reducing body fat, exercise is not nearly as effective as focusing on nutrition (ie, ‘what’ but more importantly ‘how much’ we eat) because it takes a hell of a lot of exercise to burn even a relatively small number of calories.

Consider this – an hour’s running on a treadmill may burn 400-600 calories. But there are 525 calories in a Pret BLT sandwich and 600 calories in just one small bag (100g) of ‘healthy’ almonds. So an hour of hard slog can be wiped out with a quick snack.

Equality in motion

​​When it comes to efficiency, it is far easier and quicker (instant, in fact) to reduce calorie intake via food (by eating less of it) than it is to exert yourself for long periods. Moreover, particularly if you are not used to it, having done the vigorous exercise, you may feel hungrier than if you had not. In that sense, using exercise as your prime weapon against body fat could be self-defeating.

(At this point it may be worth drawing a distinction between cardiovascular and resistance exercise. Bodyscan clients’ best fat-loss results come from a combination of calorie-cutting and weights-based training. It is still true that the exercise does not burn many calories (an hour of weights in the gym may burn around only 200-300 calories) but the muscle-building effect of resistance work improves the ‘quality’ of the weight loss – in other words, most if not all of the weight loss is fat.

We had one client who lost 21kg of weight and a staggering 20kg of it was pure fat. This was achieved through aggressive calorie-cutting and a disciplined resistance programme five to six days every week to preserve muscle. (Of course, the only way of being sure was because of his DEXA scan. It’s normal to see a fat-to-lean loss ratio of only 3:1, and we have seen as bad as 1:5. Yes! Weight loss of 6kg but only one kilo of it was body fat. What seems a good result on the bathroom scales can be shown by DEXA to actually be a very poor result.)

While exercise itself may not burn many calories, we are not for a moment suggesting you don’t do it. Far from it! Exercise is good for you. Whether you schedule formal exercise in your day, play team sports or simply walk rather than drive, moving is good for mind, body and soul. But if you are looking to lose body fat, use nutrition as your primary weapon to reduce your energy intake, do some weights to maintain lean mass and use exercise to increase the gap between the number of calories you consume and the number you expend.

When it comes to F-words, focus on food for faster fat-loss!

Philip Chant

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