For people trying to lose weight or feel more in control of their eating, intermittent fasting has become a growing diet trend over the past few years.
From social media influencers to celebrity trainers, the idea of eating only during certain hours – and fasting for the rest – has been praised as everything from a detox miracle to a longevity booster.
But the science and studies proving such claims are limited – and many may question how healthy it is to skip breakfast in places like Andalucia, when temperatures soar past 30C or even 40C in summer.
What is intermittent fasting?
At its core, intermittent fasting (IF) isn’t a diet in the traditional sense, as there are no food restrictions, just timing ones.
The most common versions include:
- 16:8 method – fasting for 16 hours (usually overnight) and eating all meals within an 8-hour window.
- 5:2 method – eating normally for five days of the week and restricting calories (around 500–600 per day) on the other two.
- Alternate-day fasting – fasting or heavily restricting intake every other day.
What does the evidence say?
Research into IF is still developing, but several well-designed studies have shown it can be effective for short-term weight loss.
A 2022 review in the journal JAMA Network Open found that intermittent fasting helped participants lose around the same amount of weight as traditional calorie restriction.
The difference was mainly that many found IF easier to stick to.
Other studies suggest it may improve insulin sensitivity, reduce inflammation and support metabolic health.
However, scientists also warn that long-term data are limited and that some of the claimed benefits – such as increased lifespan – are based on animal rather than human studies.
Potential downsides
As I tell my clients, intermittent fasting isn’t for everyone. People with diabetes, low blood pressure, eating disorders, or those taking certain medications should avoid fasting without medical supervision.
Skipping breakfast or delaying meals can lead to fatigue, dizziness and poor concentration – especially during Andalucia’s hot summer months when hydration and regular energy intake are crucial.
Some people also find that fasting triggers overeating during the eating window, undoing any calorie deficit and sometimes encouraging an unhealthy ‘feast and famine’ relationship with food.
Does it help with weight loss?
Fasting can help with weight loss but only if it helps you naturally reduce your total calorie intake.
The main mechanism behind intermittent fasting is that by limiting the hours you eat, you’re likely to eat fewer calories overall. It’s not that fasting magically burns fat, but that you’ve reduced opportunities to overeat.
In Spain, where late dinners are a cultural norm, adjusting eating hours can be more complicated.
For example, a 16:8 plan that finishes eating by 6 pm may not fit Andalusian social life.
A better approach for locals or expats might be a 12:12 or 14:10 window – starting breakfast a little later and finishing dinner slightly earlier – which still provides benefits without disrupting your social rhythm.
What about muscle and metabolism?
If not managed properly, fasting can reduce lean muscle mass, particularly if protein intake is low. That’s why combining any fasting plan with adequate protein and strength exercise is key.
The idea that fasting “slows metabolism” has largely been debunked, but prolonged severe restriction can still have that effect over time. Therefore, moderation and flexibility are crucial.
A balanced approach for Spain
In Andalucia, where lifestyle, social eating and climate all influence our habits, an extreme approach to fasting is rarely sustainable.
Instead, I advise clients to focus on:
- Eating balanced meals based on the Mediterranean pattern (olive oil, fresh vegetables, legumes, fish, nuts, fruit).
- Avoiding late-night snacking.
- Allowing your body at least a 12-hour overnight fast – which most people can achieve naturally.
This gentle version, known as time-restricted eating, fits easily into Spanish life and offers many of the same metabolic benefits without the stress or deprivation of strict fasting plans.
So while intermittent fasting can support weight loss and metabolic health, it’s not a miracle solution, and its success depends on what you eat, not just when.
For most people, a balanced Mediterranean diet with moderate meal timing, regular activity and mindful eating remains the healthiest long-term approach.
