Intermittent fasting

Intermittent fasting: What has been proven – especially for blood pressure?

16:8 - fasting for 16 hours per day

Intermittent fasting involves eating patterns with set periods during which no food is consumed. Common variations include:

16:8 (16 hours of fasting, 8-hour eating window)
14:10
5:2 (significantly reduced calorie intake on two days per week)
Alternate-day fasting (fasting every other day)

Many people hope this will help them lose weight and improve their blood pressure. The scientific evidence shows that the benefit for weight loss is limited – but there are interesting indications of positive effects on blood pressure.

Does intermittent fasting work better than a conventional diet?

A large systematic review by the Cochrane Collaboration involving more than 20 studies shows:
Intermittent fasting leads to weight loss.

However, compared with a conventional calorie-restricted diet, the weight loss is not clearly greater.
There is no clear evidence that intermittent fasting is fundamentally superior to other forms of dieting.
This means that people who do well with intermittent fasting can use it to lose weight. However, it is not a “superior specialist approach”.

How does intermittent fasting affect blood pressure?

This is where it gets more interesting.

1. Measurable reduction in blood pressure
Several studies show that intermittent fasting can lower systolic (upper) and diastolic (lower) blood pressure. The average effects are in the range of a few mmHg – comparable to other lifestyle measures.
Even small reductions can lower the risk of cardiovascular disease over the long term.

2. 24-hour blood pressure
Particularly pronounced effect with alternate-day fasting
A clinical study (PMID 40911525) compared various diets, including:

time-restricted eating (e.g. 16:8)
traditional calorie-restricted diet
modified alternate-day fasting

Blood pressure was measured over 24 hours using an ambulatory blood pressure monitor.

Result:
Modified alternate-day fasting showed the most pronounced improvements in 24-hour blood pressure.
Notably:
The improvements could not be explained solely by weight loss. This suggests that fasting periods may have direct effects on blood vessels and metabolism.

3. Extended overnight fasting – even without dieting
Another study examined an approach that is very easy to incorporate into everyday life:
Participants were asked to eat their last meal at least three hours before going to bed. The aim was to extend the overnight fasting period without deliberately reducing calories.
Results after several weeks:

The nighttime drop in blood pressure (“dipping”) improved.
Nighttime heart rate decreased.
Metabolic markers showed favorable changes.

Why is this important?
Blood pressure normally decreases during sleep. If this nighttime drop does not occur, the risk of cardiovascular disease increases. A longer overnight fasting period may help support this natural rhythm.
The same was true here:
The effects occurred independently of significant weight loss.

What does this mean overall?

The scientific evidence can be summarized as follows:

Weight loss: Weight loss is possible with intermittent fasting, but it is usually no more effective than a conventional diet.
Blood pressure: Several studies show beneficial effects.
Independent of weight: Some improvements – particularly in 24-hour blood pressure measurements and nighttime blood pressure – do not appear to be explained by weight loss alone.
Meal timing matters: Avoiding late meals in particular could be beneficial for blood pressure.

Practical advice

Anyone who would like to try intermittent fasting for their blood pressure can consider the following points:

Have your last meal approximately 3 hours before going to sleep
Eat at regular times
Avoid very late, large meals
Continue to eat a balanced, low-salt diet

Important:
People with diabetes, people who are underweight, people with eating disorders, or those who take certain medications should seek medical advice before starting.

Conclusion

Intermittent fasting is not a miracle solution for weight loss.
However, there are several indications that it has positive effects on blood pressure – even when body weight changes only slightly.
In studies, a longer overnight fasting period and certain fasting approaches, such as alternate-day fasting, have shown beneficial changes in 24-hour blood pressure.
Intermittent fasting may therefore be one component of lifestyle treatment for high blood pressure – alongside exercise, weight management, and a low-salt diet.

This article is from Tensana – the leading app since 2011, helping hundreds of thousands of people monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 02/2026).

Author Horst Klier has been closely involved with high blood pressure since 2002 – initially because he was personally affected and, since 2009, as the developer of Tensana – and is now regarded as a recognized blood pressure expert thanks to his app and specialist platform, used millions of times, as well as his numerous publications. As the author of several health guides and specialist articles, he communicates complex knowledge in a clear and practical way.