It can be a tough slog, but the exercise is worth it.

In fact, if you look at the research on exercise alone, it is pretty ineffective for weight loss — and if it does work — one will have to work out at pretty intense levels day in and day out to see results.

Diet alone may not be the answer, either. Eating less each day will no doubt see the number on the scales head south, but it doesn’t differentiate the type of tissue (muscle vs. fat) your body is losing. Here’s why.

Back to the calories in vs. calories out equation, food represents 100 per cent of energy intake, as opposed to exercise which only accounts for roughly 10-15 per cent (maybe higher in a very active person) for energy expenditure — so just on that basis it’s much easier to eat less calories than to burn them.

So it may be true that “eating less” appears to be a more effective intervention for weight loss, but the question is whether you can sustain “low calorie” eating over the long term — that’s why ‘fad diets’ never really work.

Rather than helping us to reach our target weight more quickly, severely restricting calories actually reduces calorie expenditure in an attempt to maintain energy balance and prevent starvation. What this does is prevent our bodies from burning unwanted fat stores effectively which means that weight loss slows down.

The real solution comes from combining the two. Improving eating habits will help shift the weight, and exercise will help keep it off.

Is 30 minutes of exercise each day enough? When dropping kilos is your goal, the recommendation is slightly more: an hour per day, five times per week, and we’re talking heart-pumping exercise, not a leisurely stroll around the block.

“Aside from weight loss, regular exercise has benefits beyond the scales” says Professor Timothy Gill from the school of public health nutrition & research at Sydney University.

“The health outcomes you get from exercise is irrefutable. Exercise plays a protective effect against obesity related health risk”.

The takeaway

The answer is yes — you do need exercise for fat loss, but it isn’t the only factor in the equation. Almost all fitness experts would agree: exercise is medicine — and the best exercise is the one you enjoy and likely to stick with long term.

— Kathleen Alleaume is a nutrition and exercise scientist and author of What’s Eating You? Follow Kathleen on Twitter at @therightbalance