There is something more than a little unnerving about standing in nothing but your knickers and a pair of high heels, surrounded by mirrors and faced by a total stranger. It is a scenario that forces you to take a serious look at your body. Seeing yourself practically naked from every angle is rather a revealing experience, in more ways than one.

So how was it that I found myself in this position, on more than one occasion, last week? The answer is far less salacious than you may imagine: I was in fact wedding dress shopping.

This was an experience that I’d been both looking forward to and dreading in equal measures. There is a certain amount of pressure in trying on a dress that is ten times more expensive than anything that you’ve previously even contemplated taking off the hanger, and which you hope will make the man of your dreams fall even more madly in love with you, while simultaneously wowing all other onlookers.

I’ve joked here before about ‘shredding for the wedding’ but suddenly, stood there, naked but for a thong and some killer heels, and faced by some truly beautiful dresses, I really wanted my body to be the absolute best version of itself when I put them on.

For me this ideal version doesn’t mean skeletal or skinny, but strong and toned. A body with powerful glutes and legs that can run marathons, with toned arms that can climb walls and power me through the pool and with a solid core that can carry me through my asanas and hold me in an array of yoga poses.

So, how to get this mythical body in just six months?

Fortunately marathon training means that I’m getting plenty of cardio exercise in. Less fortunate is that fact that a lot of my sessions are long and slow – moderate and low intensity training, which has been shown to be linked to an increase in appetite and in compensatory eating after training (curses). So to supplement my long runs I’m putting in a couple of high intensity session each week, combining a Kayla Itsines workout with speed intervals on the bike.

In a recent episode of the Ben Greenfield fitness podcast (my new podcasting addiction) Greenfield cited a study that suggested short-term high intensity, intermittent training could assist in increased fat loss, when compared to moderate intensity, continuous exercise. The test subjects undertook 15 x 60 second bouts of cycling followed by 30 seconds of recovery three times a week for a six week period. The result was a significant decrease in fat mass (up to 12lb), while their diet remained constant.

What Greenfield also noted was that with high intensity training you don’t get the same increase in appetite as with the low intensity alternative. One of the proposed mechanisms for this is that with high intensity training you produce a lot of lactic acid and this can not only shut down your appetite but it can also be converted into glucose, via a process called the Cori cycle, which then provides more energy for your body, preventing a spike in appetite. So more HIIT for me.

In the same podcast Greenfield gave a run down of his top five tips for diet and nutrition, which I found incredibly useful and which really made me reflect on my current diet.

The first thing to note is that calories in and calories out are not independent variables, i.e. the amount and type of calories you eat can impact on the amount of calories you expend and different foods have different metabolic effects on your body, even if they contain approximately the same number of calories.

The example given in the podcast is of a test with two sandwiches – one ‘whole food’ sandwich of multigrain bread and cheese and one ‘processed food’ sandwich, made with white bread and a cheese spread – both with a similar micro-nutrient content (i.e. the same amount of carbs, protein and calories). The results showed that the postprandial metabolic rate of the people who ate the ‘whole food’ sandwich was almost twice that of those who ate the ‘processed food’ sandwich, with 137 calories being expended in digestion in the first instance and only 73 calories in the second. This is in part due to the high fibre content of the first sandwich,which requires more energy to process. Protein is also a good example of a foodstuff which takes a lot of energy to digest. In fact it uses more energy than either fats and carbohydrates, making it a potentially good source of calories.

It is also important to note that not everyone responds to calories equally. For example, insulin resistant individuals tend to respond better to a lower carbohydrate and higher fat diet, while insulin sensitive people can thrive on a higher carb diet. Your body fat and muscle percentage can also impact on how your body stores carbohydrates. The more muscle you have the more likely the carbohydrates will be stored as glycogen, whereas the less muscle you have the more likely it is that the carbohydrates you eat will be processed by the liver and stored as fat – a good reason to get into the gym and start pumping iron!

Moreover, that there is no ‘one size fits all’ method of dieting and your genetics and ancestry may have a role to play in how your body responds to food. For example, the gene that code for salivary amylase production, the AMY1A gene, can vary from person to person. The more salivary amylase you produce in response to carbohydrates the less likely those carbohydrates are to spike your blood glucose and the better your body is able to deal with them. The result may be that you are able to eat carbohydrates without excess weight gain versus someone without this genetic variation, who would be better suited to a lower carbohydrate diet. Similarly, there is something called the lactase persistence gene, which is an adaptation resulting in lactase being continued to be produced into adulthood, allowing you to continue to process milk even as an adult. This would mean that you would be able to better metabolise dairy products without digestive irritation. Having the MTHFR mutation means that you are someone who would need to take in a lot of folate into your diet. This is found in a lot of green leafy vegetables, lentils, and beans and so you might find that you are naturally drawn to a plant-based diet. The list goes on but you get the picture – just because a particular diet worked really well for a friend or colleague doesn’t mean that it will work in the same way for you.

Greenfield also flagged the importance of recognising the roles of both digestibility and nutrient density of foods. Nutrient dense foods may not always be easy to process by the body and may require fermenting, soaking, or cooking before eating to ensure that you are able to absorb all of the goodness found within them. Quinoa, for example, requires soaking, rinsing and cooking before it can be eaten, soy products are better eaten once fermented, and sourdough bread is more easily digested than unfermented alternatives. On the flip-side, some foods are very digestible but have minimal nutrient density, for example, sugars can be broken down easily by the body but offers little in the way of a nutritional reward.

Another interesting insight, and one that I suspect I am guilty of, is that in general we are eating too much and too often. Greenfield suggests that you should aim to eat two to three meals a day – breakfast sometimes, lunch and dinner. He noted that grazing, even on healthy snacks – nuts, seeds, energy bars, trail mix, dark chocolate etc. – results in the calories mounting up.

There is actually very little evidence that grazing or snacking plays a role in elevating your metabolism, but there is a lot of evidence to suggest that restrictive eating and intermittent fasting can increase fat oxidation. So a few less handfuls of nuts between meals for me then!

Overall I know that I’m lucky that I have a healthy body, that I love exercise and that I’m drawn to healthier food choices. I think it is so important to be compassionate to yourself (a trait that I’ve perhaps lacked in in the past), and I have no plans to punish my body into shape. But I know with a little bit more mindfulness around my eating, and variety of exercises I can drop a few pounds, gain a bit of muscle definition and hopefully look (almost) as good as the wedding dress I bought!