Brendan’s Personalized Fasting Diary
Giving Me Back the Control of My Health and Weight with ‘Reduced Frequency Eating’
The concept of control over food and ultimately our weight is something that probably seems almost impossible to most people in our modern, abundant society. For millennia our bodies have evolved to allow us to survive when food was scarce. Humans have developed complex biological processes that efficiently store any excess food (during feast) as energy to be utilized later in the absence of food (during famine). However, these processes that have helped us survive into the new millennium are now working against us in our modern society, when energy-dense food is abundant and physical activity is largely unnecessary.
Traditional Restriction Diets
No matter how hard we look for potential solutions to cheat the system, if we get the energy balance wrong and consume too much food or don’t burn off enough energy, we will store this excess energy for future potential famine. Many theories have been proposed about restricting certain macronutrients (e.g., Atkins, Dukan), foods from certain regions (e.g., Mediterranean) or eras (e.g., Paleolithic), eating at certain times of the day (time-restricted fasting) or on alternate days (alternate-day fasting). But in the end, if total calories consumed are greater than calories burned, your body will store the excess energy. Most claims for these traditional diets seem to defy logic, and clinical research confirms that no one diet consistently outperforms others in helping people lose weight.
One classic randomized trial compared four popular restricted-diet approaches: Atkins (low carb), Ornish (low fat), Weight Watchers (portion/calorie control) and Zone (low glycemic index). At one year, weight loss averaged 4.6 lb for Atkins (53% adherence), 7.3 lb for Ornish (50%), 6.6 lb for Weight Watchers (65%) and 7.1 lb for Zone (65%)—all modest and hampered by low adherence. The authors concluded that “each popular diet modestly reduced body weight and several cardiac risk factors at 1 year and that overall dietary adherence rates were low.” (Dansinger et al., 2005)
Traditional Fasting Diets
Traditional diets assume a one-size-fits-all approach, but personalized nutrition has revealed genetic variation in how we process food. Fasting diets gained popularity because they remove the need for constant willpower: you abstain from eating at set times, then eat freely the rest of the time. The two main styles are:
- Alternate-day fasting: Eat 25% of regular intake on a fast day, then up to 125% on a feast day.
- Time-restricted eating: Consume all calories within an 8-hour window each day (e.g., 10 am–6 pm).
The 5:2 Fast Diet splits fasting days across the week (fast 2 days, eat normally 5 days), offering flexibility while maintaining the same weekly calorie reduction.
My Personalized Fasting Journey
From childhood “puppy fat” through gym years and college excesses, I maintained a healthy weight until Oxford MBA life introduced heavy drinking and study stress—ballooning me over 200 lb. Back in New Zealand in 2011, I tried the Dukan diet (high-protein, no carbs/fat) to return to 185–190 lb, but it was unsustainable long-term despite exercise and Calocurb support.
Looking at the Research
Scientific consensus holds that lifestyle changes—healthy eating patterns, reduced caloric intake and physical activity—are the basis for long-term weight loss. (NIH, 2015) I already exercised regularly and ate reasonably well, but refused to sacrifice weekend social drinking. The only lever left: reduce overall calorie intake. Research suggests a 25% weekly calorie reduction is effective for weight loss.
Personalized Calorie Reduction
A continuous calorie-reduced diet wasn’t for me, so I examined fasting approaches. I discovered Dr. Krista Varady’s “Every Other Day Diet,” which achieves the same weekly calorie cut as daily restriction while fasting only alternate days:
However, fasting one weekend day was impractical for my lifestyle. I preferred the 5:2 split—dieting only 2 days each week—so I dived deeper into its clinical evidence and user feedback.
A JAMA trial (2017) found that alternate-day fasting did not outperform daily restriction in adherence, weight loss or cardioprotection—and had higher dropout rates. Ultimately, personal preference and sustainability matter most. I chose the 5:2 Fast Diet for its balance of efficacy and lifestyle fit:
Reduced Frequency Eating
While portion sizes have grown, research correlates the obesity epidemic more closely with increased eating frequency than portion size. (Mattes, 2014) Conventional advice promotes small, frequent meals, but controlled trials show no benefit for weight loss or maintenance from higher meal frequency. Our bodies are adapted to feast-and-famine cycles, not constant snacking.
Benefits of Fasting
Fasting enhances metabolic flexibility—the ability to switch between burning carbohydrates and fat. After an overnight fast, the body shifts to fat oxidation. (Kelley, 2005; Wolfe, 1998) Stretching time between meals trains your body to burn fat more efficiently and reduces total insulin exposure, promoting fat release. (Melzer, 2011)
Resting Energy Expenditure
On continuous calorie restriction, the body defends against weight loss by lowering resting energy expenditure (REE) and increasing hunger. But intermittent fasting—by avoiding constant stress—can preserve REE. One study even showed a ~5% REE increase during early fasting days. (Siervo et al., 2015; Catenacci et al., 2016)
Hunger
Heightened hunger is the primary challenge of dieting. Dropout rates at 12 months reach 38% for low-fat and 48% for low-carb diets. Feelings of hunger can increase by nearly 75% after 15 weeks on a 25% calorie-reduced diet, making long-term adherence difficult.
Working with Our Own Biology
Effective weight management must respect our evolutionary biology. Intermittent or reduced-frequency eating leverages feast-and-famine adaptations to optimize fat burning, preserve metabolism and manage hunger—while fitting personal preferences and lifestyles.
