Intermittent Fasting: What Do the Most Recent Studies Say About This Practice in 2025?
Does intermittent fasting help you lose weight? Is it safe? Are its benefits scientifically proven?
These are some of the most common questions people ask before adopting this eating strategy. In 2025, science continues to advance, offering increasingly accurate answers. At Clínica Débora Ayala, as professionals of integrative health, we believe that understanding the systemic effects of fasting also contributes to oral health and the overall balance of the body.
In this article, we’ll explore what the most up-to-date studies say about intermittent fasting, its potential health benefits, and the precautions you should consider before starting this practice.
What is intermittent fasting and why has it become so popular?
Intermittent fasting consists of alternating periods of eating with periods of caloric abstinence. There are various protocols, such as 16:8 (16 hours of fasting and 8 hours of eating), 4:3 (three non-consecutive fasting days per week), and alternate-day fasting, where fasting takes place every other day.
This approach has gained popularity for its promise of weight loss, improved metabolism, reduced inflammation, and even increased longevity. But do scientific studies support these claims?
Does intermittent fasting really help with weight loss?
Yes. Recent clinical studies indicate that intermittent fasting can be as effective as traditional daily calorie-restriction diets. A meta-analysis published in 2025, which reviewed nearly 100 clinical trials, showed an average weight loss ranging from 1.3 kg to 4 kg depending on the protocol followed.
Additionally, participants who followed the 4:3 method lost up to 2.7 kg more than those who followed continuous calorie restriction alone. In other words, it is possible to lose weight through fasting — but with guidance and the right strategy.
Beyond weight: can fasting improve metabolic health?
Yes, and this is a key point. Studies show that intermittent fasting improves insulin sensitivity, regulates cholesterol and triglyceride levels, and reduces inflammatory markers such as C-reactive protein (CRP).
Another area of growing research is fasting’s impact on autophagy — the body’s natural cellular renewal process. This contributes to the prevention of neurodegenerative and cardiovascular diseases. While promising, this field still requires more robust studies to confirm long-term effects in humans.
Is fasting safe for everyone?
Not always. Despite the positive outcomes, intermittent fasting is not recommended for everyone. People with diabetes, chronic illnesses, eating disorders, pregnant or breastfeeding women, and the elderly must undergo individual medical evaluation before starting.
In some cases, restrictive protocols such as 8-hour eating windows may lead to drops in blood pressure, hypoglycemia, dehydration, or even binge eating episodes. This highlights that no eating strategy should be adopted without professional guidance.
What is the link between intermittent fasting and oral health?
This is a less talked-about connection — but an essential one. During prolonged fasting, reduced salivary flow is common, which may lead to dry mouth, bad breath, gum sensitivity, and changes in the oral pH.
Saliva is one of the mouth’s primary natural defenses. It helps protect against bacteria, maintains pH balance, and assists in tissue regeneration. When there’s an imbalance due to prolonged fasting or poor hydration, conditions arise that increase the risk of cavities, gingivitis, and oral infections.
That’s why at our clinic, we always emphasize: any dietary change also impacts your oral health. Dental monitoring is essential during any lifestyle or habit shift — including intermittent fasting.
Does intermittent fasting replace diet or treatment?
No. Fasting can be a complementary tool, but it doesn’t replace a balanced diet, nutritional education, or the support of healthcare professionals. What works for one person may not be suitable for another.
Moreover, adopting fasting just because it’s trendy or without understanding your body’s signals may lead to frustration, rebound eating, and even hidden oral issues like bacterial plaque buildup caused by changes in saliva production.
When should you seek a specialist?
If you’re considering starting intermittent fasting or have already begun and noticed changes like bad breath, dry mouth, increased sensitivity, or altered taste, it’s time for a professional assessment.
At Clínica Débora Ayala, we take a holistic approach to your health. We evaluate not only your mouth but also your medical history, eating habits, and the effects of new practices on your overall well-being.
Your health begins in your mouth
Intermittent fasting can be an effective and safe practice — when done with responsibility, knowledge, and professional support. Just as each body reacts differently, every smile deserves individualized care.
Clínica Débora Ayala is here to guide you through this process with scientific foundation, empathy, and integrative care.
Schedule your consultation and learn how to take care of your oral health — even while fasting.
Sources
- Harvard School of Public Health – Intermittent fasting may be effective for weight loss and cardiometabolic health (hsph.harvard.edu)
- Veja Saúde – Afinal, jejum intermitente pode mesmo ajudar no emagrecimento? (veja.abril.com.br)
- Verywell Health – 4:3 intermittent fasting outperforms daily calorie restriction in weight loss (verywellhealth.com)
- NY Post – 3 months of this ‘relatively simple’ diet can cause significant weight loss (nypost.com)
- Health.com – This Intermittent Fasting Method Outperformed the Rest (health.com)
- Thesis Editora – Revisão sobre jejum intermitente (ojs.thesiseditora.com.br)
- Times of India – Science-backed health benefits of fasting (timesofindia.indiatimes.com)
- Correio Braziliense – Pesquisas concluem que dietas restritivas e jejum têm efeitos semelhantes (correiobraziliense.com.br)
- Wikipedia – Intermittent fasting (en.wikipedia.org)
- Nobel Prize – Yoshinori Ohsumi and the discovery of autophagy (nobelprize.org)
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