I’ve always found it difficult to lose weight slowly. I’m a hearty eater and sometimes see food as a reward at the end of a stressful day. Once I start, self‑control can be hard—but, paradoxically, strict abstention is much easier. I’m not obese thanks to regular sport, yet—with the “beach‑body readiness” pretext—I decided to shed a few extra kilos.
The Intermittent Fasting Diet
A few weeks ago I chose to adopt intermittent fasting (IF). I’m not new to it: I often eat once a day, so between one meal and the next I wait ~23 hours. The goal is to concentrate meals in a small window: 8 hours or less (down to one meal a day, but not beyond). It can be practiced daily, on alternate days, or only on certain days of the week. The approach emulates natural cycles of abundance and shortage: in nature an adult would likely have one main meal per day with some snacks, not the six balanced meals many diets consider indispensable.
The concepts that follow represent my personal experience. Before adopting IF I strongly recommend consulting a doctor.
Benefits
The main benefit of adopting a small eating window is that it gives the body—especially the digestive system—time to “reset”. Food we ingest, often chemically altered through cooking, can be a source of micro‑irritation: not enough to be noticed acutely, but enough to contribute to heaviness and low energy. Because that state can become habitual, the improvements are often perceived only after some persistence.
Most people pursue IF for weight loss. IF is usually paired with some level of caloric restriction, depending on one’s condition and goals. It’s useful to understand the rough order in which the body taps energy reserves:
- Food in the digestive tract
- Glycogen in muscles and liver
- Fat stores
- Muscle/lean mass and other tissues
To achieve a lean physique, IF should be practiced without ever reaching stage 4, which would mean unacceptable loss of lean mass and potential health risks. A minimal lean‑mass loss can occur even in stages 2–3; extra protein and amino acids can help compensate.
During fasting (as with any caloric restriction), deficit comes from basal metabolic rate (BMR) plus physical activity. After ~48 hours many people enter stage 3: the liver shifts toward producing ketone bodies, which the brain can use as alternative fuel; other tissues can rely on fatty acids from adipose tissue.
Day by Day
To commit to IF it helps to understand the link between energy expenditure, metabolism, and weight. My estimated BMR is ~3105 kcal/day; you can estimate yours online, though I prefer a fitness tracker (e.g., the Fitbit Charge HR) that also accounts for daily activity.
Roughly 1 lb of fat ≈ 3500 kcal. A day with zero intake, for a body like mine, could mean almost half a pound lost. Calories remain an imperfect unit and energy expenditure is estimated, so it’s important to monitor weight, physique, and energy levels to draw conclusions.
During extended IF (1+ weeks) BMR may down‑regulate in response to deficit. You can counter by keeping expenditure high and (optionally) using thermogenics like caffeine or green‑tea extract (EGCG).
The lower BMR is a double‑edged sword: breaking a fast while in “power‑saving mode” encourages storing every extra calorie as fat (yo‑yo effect). Re‑feeding should therefore be gradual, increasing calories and lengthening the eating window progressively. Fortunately, fasting itself helps build the habit of saying no to too much food.
In my daily meal I aim for quality food (home‑made, plenty of vegetables) and at least ~1000 kcal, sometimes supplementing vitamin C, vitamin D3, magnesium/phosphorus, and omega‑3s to replenish micronutrients. A decent protein share (≥30%) helps limit muscle catabolism. Hydration matters, too: drink plenty to compensate for fluids you’d normally get from food.
My long‑term goal is ≤10% body fat (for men, typically a well‑defined, toned look). For women a comparable target is ~15–20%; competitive bodybuilders (male) often go for 6–7%. I track with impedance devices like the Withings Smart Body Analyzer and the Skulpt Pulse for spot checks.
It’s Personal
There are many variations of fasting. Some aim to maximize recovery, hormones, and circadian rhythms; others are less invasive and easier to adopt (e.g., 5:2: five normal days and two fasting days). The formula is customizable, but the principle remains: skip meals intentionally. Once you learn to fast properly, you can tailor it to your needs.
To obtain faster results I chose longer fasts with very low intake and daily activity, though I still have two meals on special occasions. This approach helped me lose ~8 kg in a month. When the “cutting” phase is over, I’ll switch to a 5:2 pattern for maintenance.