My mum would call it ‘puppy fat’, which is supposed to be an endearing term for ‘fat on the body of a baby or child which disappears around adolescence’. However, I was always conscious that I was taller but also a bit fatter than the other kids. This larger size helped me in some sports, but it was not until a mistimed comment from an extended family member that I became motivated to try to be a more ‘normal’ size.

The teenage years are the hardest for self-consciousness and why mistimed comments can have a much larger impact than intended. But as a result, at the age of 14 I joined a gym despite advice that weights at that young age can affect normal growth. The increased exercise worked for me, and I was able to maintain a healthy weight until the end of high school. That is, until I discovered social drinking.

Leaving high school at 172lb (at 6’1” this was a BMI of 22.7 and right in the middle of the healthy range), I have always struggled to keep my BMI in the healthy range below 25 (or below 190lb) since. Poor nutrition and excessive drinking during college didn’t help. However due to my higher-than-normal consciousness of weight (set at a very early age), I never let my weight get too much above 185lb.

As I imagine happens to a lot of us however, something changed when I reached 30. I took a year off work to undertake my MBA at the University of Oxford in England. With a return to the excessive drinking and a lack of exercise due to study, I gained over 200lb (BMI of 27) and was no longer the healthy person I had been my whole life.

At the end of my study in 2011, my wife and I moved to New Zealand, and I decided to retake control of my weight. Returning to work, I was once again in a routine to be able to start regular exercise. 2011 was also the year that the Dukan diet (removing carbs and fat from the diet) was extremely popular and I decided to try it out. I love meat and dairy, and it is easy to get high-quality, low-cost protein in New Zealand, so this diet worked really well for me and I was able to get back down to my previous 185-190lb weight. Ultimately however, the diet was not sustainable for me due to the restricted nature of the diet, but I was able to keep off any extra weight gain through exercise (up to 5 times a week) and removing snacking from my diet during the week.

Looking at the research

Reading the latest scientific articles, it quickly became clear that there is no consensus in the academic world about the longer-term sustainability of traditional diets. And there is certainly no evidence that any one traditional diet is better than any other based on clinical evidence despite their popularity. It appears that the only consensus that can be reached by health experts is that ‘making lifestyle changes – including following a healthy eating pattern, reducing caloric intake, and engaging in physical activity – is the basis for achieving long-term weight loss’ (National Institutes of Health, 2015).

I was already engaging in physical activity up to 5 times during the week when work allowed and very rarely less than 3 times a week. I also ate reasonably healthily and didn’t want to restrict my diet anymore based on the traditional restriction diets, which I had tried before with the Dukan diet. Finally, and perhaps most importantly, I made the decision that to make any dietary changes sustainable for me, I was unwilling to sacrifice my social life or my social drinking in the weekend. Therefore, the only lever I had to make a change in my lifestyle was to reduce my calorie intake. Research into the calorie restriction needed for weight loss, it appears you need to reduce your weekly calorie intake to approximately 75% of your normal calorie intake to be effective.

Personalized Calorie Reduction

I knew from the start that a regular calorie-reduced diet would not work for me. As can be seen in figure 2, I know that I just don’t have the willpower to be able to stick to a diet that is 24/7 (like the portion and calorie restriction of a Weight Watchers type diet). I am very social in the weekend and tend to overeat during these two days, while I have much more self-control during the week.

Figure 1: Regular calorie-reduced diet. Calorie reduction required over the week to lose weight

Weight	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
Maintenance	100%	100%	100%	100%	100%	100%	100%	100%
Loss	75%	75%	75%	75%	75%	75%	75%	75%

I found a diet that appeared to suit me a lot more. The 5:2 Fast Diet has been extremely popular in the UK, while not quite so popular in the US. At its most basic, it involves 2 days of fasting (eating a controlled number of calories - 500 calories for women and 600 calories for men) and 5 days of eating ‘normally’. I liked the concept that I would only have to be consciously dieting for 2 days and enjoying life for the rest of the week. It was the first traditional diet to split the calories out into a ‘weekly calorie intake’, which seemed to make sense to me and fit into my way of living.

So, I started to do some research into the diet and found that there was very little clinical research into the 5:2 Fast Diet. However, the original advocate of alternative-day fasting was a researcher in the US by the name of Dr Krista Varady from the University of Illinois with her ‘Every Other Day Diet’. She was doing a lot of research into alternate day fasting, which over the week gives the same calorie reduction to a regular calorie-reduced diet (figure 3).

Figure 2: Alternate day fasting. Calorie reduction required over the week to lose weight

Diet	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
Regular	75%	75%	75%	75%	75%	75%	75%	75%
Alternate-day	25%	125%	25%	125%	25%	125%	25/125%	75%

The key idea of the diet is to reduce calories to 25% of regular calories on one day (fast day) and ‘eating anything you want and all you want, every other day’. Feast day was estimated to be 125% of your normal calorie intake. The average of the two days would give you the same overall calorie reduction as a regular calorie-reduced diet. “Alternate-day fasting has been promoted as a potentially superior alternative to daily calorie restriction under the assumption that it is easier to restrict calories every other day” (Trepanowski, et al., 2017).

However, in a gold standard weight loss trial published in the Journal of the American Medical Association in May 2017 comparing the alternate-day fasting diet versus regular daily calorie restriction, “Alternate-day fasting did not produce superior adherence, weight loss, weight maintenance, or cardio protection versus daily calorie restriction.

Rather, it appears as though many participants in the alternate day fasting group converted their diet into de facto calorie restriction as the trial progressed. Moreover, the dropout rate in the alternate-day fasting group (38%) was higher than that in the daily calorie restriction group (29%) and the control group (26%). It was also shown that more participants in the alternate-day fasting group withdrew owing to dissatisfaction with diet compared with those in the daily calorie restriction group. Taken together, these findings suggest that alternate day fasting may be less sustainable in the long term, compared with daily calorie restriction, for most obese individuals. Nevertheless, it is still possible that a certain smaller segment of obese individuals may prefer this pattern of energy restriction instead of daily restriction” (Trepanowski, et al., 2017).

Because alternate-day fasting diet did not produce superior results than regular calorie-reduced dieting, it looks like it comes down to personal preference and whether alternate-day fasting fits into your lifestyle and preference for dieting every other day. I decided that alternate day fasting would not suit my lifestyle as it would mean that at least one day of the weekend, I would need to be fasting and it just wouldn’t be sustainable for me. I liked the idea with the 5:2 Fast Diet that I would only have to think about dieting 2 days a week. Comparing the three diets, while the calorie reduction wasn’t quite as high for the 5:2 Fast Diet, therefore it would take longer to lose weight, I decided to try it.

Figure 3: Comparison of the 5:2 Fast Diet to alternate-day fasting and calorie-reduced dieting 

Diet	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
Regular	75%	75%	75%	75%	75%	75%	75%	75%
Alternate-day	25%	125%	25%	125%	25%	125%	75%	75%
5:2 Fast Diet	100%	25%	100%	25%	100%	100%	100%	79%

Of all the diets that I have heard people participate in, I have heard much better feedback about the 5:2 Fast Diet and the ability for it to be sustainable for initial weight loss and then ultimately weight management. I started by reading Michael Mosley’s book ‘The Fast Diet’ and it gave some great context around the benefits of fasting. While some of the medical claims were a bit radical for me, it talked about the mental clarity (and sometimes euphoria) that people experience while fasting, so I was very interested to try it. It also gave me the context to understand that people can do days, if not weeks fasting. Surely, I would be ok for a day with only two small meals.

And I was. I must admit that it wasn’t easy, but I did quite enjoy the challenge. It did make me realize however that I had forgotten what it felt like to be hungry. I didn’t quite feel the euphoria that some people talk about with fasting, but surprisingly I did enjoy a feeling of mental clarity and certainly did not feel faint or dizzy. I managed the hunger pangs by experimenting with supplementation and I was able to find some products that work for me. In the end trying the 5:2 diet was transformative for me. Despite being difficult I did feel the benefits of fasting for myself, and I was converted.

Personalized Fasting

So, for some who try it, the 5:2 Fast Diet will work for them and they will have no need to personalize their fasting further. However, an important part of the 5:2 Fast Diet is that ‘success also depends on not over-eating on your normal days’. And for me I found I was still eating too much on the weekend and liked the alternative-day fasting idea of being able to not have to worry about what I was eating at some time during the week. And it looks like this is a common perception - according to Mintel research, for most people, committing to a long term diet is difficult and “in order to satisfy consumer’s desire to treat themselves, diet plans that account for ‘cheat’ days could produce more long term success” (Mintel, 2015).

Therefore, using the 5:2 Fast Diet as a base, I decided to personalize my fasting. The first (and easiest decision) was to make the weekend ‘cheat days’ – this means I have two days when I don’t have the think or worry about food or drink. Considering this decision, I then had to conduct 3 ‘fasts’ during the week.

Figure 4: My first attempt at Personalized Fasting 

Fasting	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
5:2 Fast	100%	25%	100%	25%	100%	100%	100%	79%
Personalized	25%	25%	25%	100%	100%	125%	125%	75%

This personalization did mean that I did reach my calorie goals for the week (75% of normal intake), but I was still struggling with reducing calories to 25% on the fasting days. On the 5:2 Fast Diet, the suggested method to reduce your calories (to 500 for women or 600 calories for men) is to take 2 small meals over the day – a regular breakfast and then a small dinner. There are now whole cookbooks that help you achieve the calorie requirement of the 5:2 Fast Diet, but still the diet wasn’t working for me. It was hard work, even with Calocurb’s support, I was very hungry towards the end of the day, and I felt like I was missing out on a full social dinner with my family.

So, I started to experiment with spreading the ‘pain’ of fasting over the course of the week. Personally, I found being ‘good’ during the week easy and the fact I didn’t have to worry about my calorie intake during the weekend was always reassuring and certainly a treat for being good during the week. Spreading the calories over the week also made the daily calorie goal seem much more achievable.

Figure 5: My second attempt at Personalized Fasting 

Fasting	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
5:2 Fast	100%	25%	100%	25%	100%	100%	100%	79%
Personalized	55%	55%	55%	55%	55%	125%	125%	75%

So now that I had my daily allocation of calories sorted for the week, I now had to figure out how to effectively halve my regular calorie intake during the week. Having done some testing with the 5:2 diet, I found that I personally needed breakfast to kick-start my day and I didn’t seem to miss lunch that much (with the help of Calocurb). I was certainly hungry by the time I got home, and this is where I found that reducing calories to 25% didn’t work for me. After a small fasting size dinner, I was still hungry. The other benefit with skipping lunch is that I would be saving up to $50 a week on lunch costs.

So, I started to investigate the split of when calories were consumed during the day and what I found seemed to make sense. Based on American nutrition surveys, the daily split of calories is shown in figure 7. The 24% of calories that are consumed as snacks was simplified into a morning, an afternoon, and an evening snack. I must be honest that I was surprised that an evening snack existed but apparently 67% of Americans have an evening snack, it was around 15% of their total daily calorie intake and was eaten about 8:20pm, 2 and half hours after dinner.

Figure 6: Meals where calories are consumed in America (Kant & Graubard, 2015)

Breakfast	Snack	Lunch	Snack	Dinner	Snack	Total
16%	8%	24%	8%	36%	8%	100%

The first personalization decision I made for myself is that dinner is my most important meal of the day due to being a treat at the end of the day and it is also a very social meal for me personally. So, I didn’t want to sacrifice any calories here. This left me with 19% of my calories to be spread over the rest of the day. For me it was an easy decision to lose the snacks (which I was already doing), which left me in an interesting position of a choice between breakfast and lunch.

You will see research and advantages of skipping either lunch or skipping breakfast. But in the end, it is personal. For me I learnt through my 5:2 Fast Diet research that I prefer the routine of breakfast and it saves me time and money at lunch. So my decision to skip snacks and lunch left me with the equation seen in figure 8.

Figure 7: My personalized dairy calorie consumption on weekdays 

Breakfast	Snack	Lunch	Snack	Dinner	Snack	Total
16%	8%	24%	8%	36%	8%	100%
16%				36%		52%

By personalizing my eating, I was now only consuming 52% of the regular calorie consumption during the week. This left me with approximately the 25% weekly calorie reduction that is recommended in the research for weight loss (figure 9). However now my way of eating was personalized to my preferences, and I knew would be sustainable for me over the longer term. And I still had my cheat days in the weekend.

Figure 8: My third attempt at Personalized Fasting 

Fasting	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
5:2 Fast Diet	100%	25%	100%	25%	100%	100%	100%	79%
Personalized	52%	52%	52%	52%	52%	125%	125%	73%

Having started to discuss Personalized Fasting with people, one of the most popular alternative preferences is for people who don’t feel hungry in the morning and therefore are happier skipping breakfast than lunch.

Figure 9: Calorie reduction when breakfast is skipped

Breakfast	Snack	Lunch	Snack	Dinner	Snack	Total
16%	8%	24%	8%	36%	8%	100%
		24%		36%		60%

While this doesn’t quite give as much calorie reduction as with skipping lunch, it is still a 20% calorie intake reduction over the week and the same weekly calorie reduction as the 5:2 Fast Diet. This is also a similar eating regime to the time-restricted fasting diet that has been popularized by the ‘8 Hour Diet’.

Figure 10: Weekly calorie intake when skipping breakfast during the week 

Fasting	Mon	Tues	Wed	Thurs	Fri	Sat	Sun	Total
5:2 Fast Diet	100%	25%	100%	25%	100%	100%	100%	79%
Personalized	52%	52%	52%	52%	52%	125%	125%	73%
Breakfast Skip	60%	60%	60%	60%	60%	125%	125%	79%

Even though I was now eating more than double that amount of food compared to a 5:2 fasting day, I still seemed to be reaping the benefits of the fasting days (mental clarity and weight loss), without as much pain. Please bear in mind this is a personalized plan for myself and what I found was beneficial based on my lifestyle.

Hunger

Probably the largest challenge that people who have lost weight will acknowledge is the significant increase in feelings of hunger while on a diet. This is the body’s primary and most recognizable response to a calorie-reduced diet. The diet becomes increasingly hard, as you become increasingly hungry. The opportunities and temptation to cheat seem to be everywhere and become irresistible.

Some diets are more difficult than others to maintain and in an analysis of weight loss studies, the dropout rate after 12 months was 38% for low-fat diets and 48% for low carbohydrate diets (Nordmann, et al., 2006). And even when weight is lost, most traditional targeted interventions struggle to sustain their impact, with weight regain ranging from 30-70% of the original loss (figure 1). As is seen in figure 13, feelings of hunger increase by nearly 75% after 15 weeks of being on a 25% calorie restricted diet. No wonder it is so hard to avoid temptation on a restricted calorie diet and the reason people dropout of diets or fail to maintain lost weight.

This is such a big issue when losing weight that it is likely we need support to overcome this increase in hunger. There are some nutritional tricks as well as supplementation tips, including Calocurb that have been proven to help. Supplementation is one of the most exciting recent advances in the science and certainly helped me on my journey to Personalized Fasting.

- Bradley (Calocurb customer since 2019)