INTERMITTENT FASTING – why, when & is it okay to skip breakfast?

Fasting, as a period of abstaining from most or nearly all food, has a long history in our society. Sometimes viewed as a punishment, and in other cases as a practice that strengthens a person spiritually or brings them closer to God, fasting remains a relevant topic today. Continuous or very frequent fasting, as well as strict restrictive diets (such as completely avoiding carbohydrates), often leave us feeling more tired, reduce focus, learning, and memory, and even when weight loss is initially successful, it is often followed by disappointment—the well-known yo-yo effect. The goal of intermittent fasting should be the opposite: after the first few (challenging) days of adjustment, appetite often decreases, strong cravings (like chocolate at 11 p.m.) become easier to control, and benefits such as better sleep regulation and increased daily energy begin to appear.

One of the most popular approaches is the 16:8 method, which both students and working adults can usually fit into their daily routines (unless you study at night—trying to focus and memorize while hungry is nearly impossible). Many people following the 16:8 method skip breakfast and eat between 12:00 and 8:00 p.m. This raises an important question: how unhealthy is skipping breakfast, and does it really have negative effects on the body—or is it largely a myth?

Skipping breakfast often causes the same level of concern in our grandmothers as sitting on a cold surface or sleeping in a draft. Not so long ago, the morning meal was essential fuel for a full day of physical work, with wake-up times between 4 and 5 a.m. (and deep sleep already by 10 p.m.). But does our modern lifestyle truly require the same approach?

Research shows that frequent breakfast skipping is linked to an increased risk of type 2 diabetes. People who skip breakfast tend to have larger blood sugar spikes after lunch and dinner, leading to higher insulin release, gradual strain on the pancreas, and potentially insulin resistance or prediabetes—the step just before diabetes. Interestingly, in individuals with insulin resistance or early prediabetes and only mildly elevated morning glucose, regular meals, avoiding simple sugars (bakery foods, we know), and losing just 5–6 kg can significantly improve lab results and delay the need for medication.

This does not mean that intermittent fasting has no benefits—only that it needs to be planned carefully. Instead of skipping breakfast entirely, the eating window can be shifted to include a later breakfast and an earlier dinner. The first meal after fasting should be nutrient-dense and low in glycemic index to prevent sharp glucose spikes. A 30-minute moderate-paced walk after the last meal is also recommended.

This combination of properly planned intermittent fasting and regular physical activity is one of the most effective ways to address insulin resistance. Poorly planned 16:8 fasting may actually worsen it—balance is key. For beginners and those with a genetic risk of diabetes, gentler approaches such as a 12:12 or 14:10 schedule are often a better choice.

Another popular form of fasting worldwide is the 5:2 method, where we eat normally for five days a week and restrict calorie intake on two days. Its appeal lies in easier adaptation, simpler meal planning, and avoiding daily restriction. This approach has been popularized by several well-known authors. However, it is important to note that on the two fasting days, calorie intake is often reduced to very low levels—sometimes below 600 kcal per day—which can be both difficult and potentially unsafe for higher-risk groups. As with other methods, careful meal timing is essential, and sudden intake of high–glycemic index foods after prolonged fasting should be avoided.

Even stricter approaches include the eat-stop-eat method, where one or two days per week involve a full 24-hour fast, and the OMAD method (one meal a day), where fasting lasts 23 hours with a single main meal consumed within one hour. These stricter regimens carry higher risks and are not sustainable long term. This raises the question of how beneficial they truly are, especially since they usually require a return to more balanced eating afterward—often accompanied by the reappearance of unwanted habits.

The point? Balance.
Intermittent fasting can, and should, be part of a healthy daily routine. Alternating between 12:12 and 16:8 schedules, planning meals carefully, avoiding high–glycemic index foods after fasting (for example—a burger in a bun!), and choosing an eating window that includes breakfast (even a later one) are a solid starting point. Early on, keeping a simple food diary—recording when and what you eat—can be very helpful. Reviewing a week or so of meals often makes it clear what needs adjusting and how balanced your first post-fast meals are.

So, when is the best time to fast?
In healthy individuals without a higher risk of diabetes, there appears to be little difference between eating windows such as 8 a.m.–4 p.m. or 12 p.m.–8 p.m. However, regularly skipping breakfast or eating heavy meals after fasting may, over time, increase blood sugar spikes—even in healthy people—raising the risk of insulin resistance. With good meal planning, the preferred 8-hour window can be chosen based on daily routine. If the goal is weight loss and better sleep regulation, an earlier window that includes breakfast and an earlier dinner (for example 10 a.m.–6 p.m.) may be more suitable, along with adequate hydration and a calming herbal tea in the evening (without sweeteners or caffeine, such as linden, lemon balm, or mint). Hydration matters: water, herbal teas, electrolytes, and mineral water can all help, with carbonation adding a feeling of fullness. Gradual adaptation is key—hunger usually fades with time.

Looking at the bigger picture, our modern habits are far removed from early rising, large breakfasts, and physical labor until dusk—but our genes are not. Only a few generations separate us from that way of life, while evolution has not kept pace with rapid lifestyle changes. This helps explain why heavy, calorie-dense meals rich in processed fats and simple sugars—often eaten after long periods without food—pose such a challenge. Stricter fasting (16:8) can be useful occasionally, while milder approaches (12:12) are often better suited for long-term habits, as long as meals are planned to avoid sharp blood sugar spikes.