Dietriffic dietitian Melanie looked into fasting recently. Some of her thoughts:
The main problem with this whole area of intermittent fasting, is that research in humans is severely lacking, and what I’ve found online is something I can only describe as ‘evangelism’ in support of this way of eating.
That’s not to say some of what is being said isn’t true, but much of it should be taken with a pinch of salt!
Anyhow, some of the research suggests intermittent fasting may lead to;
- Improved HDL levels in women, and other improvements in blood lipids for both sexes.
- Improved insulin sensitivity in men and women, but impaired glucose tolerance in women.
- Weight loss (also here).
- Blood pressure benefits.
- Extended lifespan (in rats).
- Improved cognitive function, and protection against conditions such as dementia and Alzheimer’s disease.
- One review looking at humans in terms of ‘real-world’ health outcomes, noted that intermittent fasting may have a protective effect against heart disease, type 2 diabetes and cancer. However, it concluded “more research is required to establish definitively the consequences of ADF (alternative day fasting)”.
Many of these benefits are also commonly cited for calorie restriction and exercise, which seems a more natural way to achieve better health, without the downsides of periodic food deprivation (see here and here).
One group of researchers, however, were extremely enthusiastic about this whole idea of fasting, claiming;
Since May 2003 we have experimented with alternate day calorie restriction, one day consuming 20-50% of estimated daily caloric requirement and the next day ad lib eating, and have observed health benefits starting in as little as two weeks, in insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette’s, Meniere’s) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes. We hypothesize that other many conditions would be delayed, prevented or improved, including Alzheimer’s, Parkinson’s, multiple sclerosis, brain injury due to thrombotic stroke atherosclerosis, NIDDM, congestive heart failure.
For the last year I’ve batted around the idea of intermittent fasting but haven’t pulled the trigger. If I do it, it’ll probably be for a 24-hour period.
Melanie’s a smart lady. Read the rest.