Does extra salt help with fatigue during fasting?
Baking soda (sodium bicarbonate) reduced fatigue in trained men who had fasted and then exercised, but this was found in only one small study and says nothing about everyday fasting-related fatigue. Ordinary table salt has not been studied for this purpose.
Sodium bicarbonate is baking soda, not table salt. That distinction matters: the question about 'extra salt' most likely concerns sodium, but the only available research in the context of fasting involves sodium bicarbonate. In a small study with 14 trained men who had fasted for 14 hours, fatigue during intense physical exercise decreased by 37% after taking sodium bicarbonate, compared with a saline solution used as a placebo. Anaerobic power also rose by 21%.
Notably, fasting itself in that same study improved anaerobic performance by 10% and muscular endurance by 24% compared with a fed state. Fasting therefore does not appear to be consistently detrimental to athletic performance. Whether the combination of fasting and sodium bicarbonate also does anything for non-athletes or for everyday fatigue has not been studied.
A relevant side effect: sodium bicarbonate caused mild gastrointestinal complaints in participants. For people who are sensitive to this, that is a genuine drawback.
The broader question of whether intermittent fasting produces health benefits remains unanswered for the time being. The evidence for this is very thin: the available randomised studies are small and measure primarily intermediate values such as weight and cholesterol, not whether people actually feel less fatigued. Firm conclusions about disease or mortality cannot be drawn on the basis of this research.
This answer relies primarily on one small randomised study with 14 trained men examining sodium bicarbonate during short-term fasting. The findings on fatigue and performance are therefore preliminary and apply specifically to trained men during intense exercise. The researchers themselves classify the evidence as limited. The broader claim about intermittent fasting and health rests on a review study that concludes only three small randomised studies exist, all focused on intermediate outcomes. Evidence on fasting and fatigue in the general population is absent.
Do you live longer if you eat more salt?
Eating more salt does not lead to a longer life. At the individual level, it demonstrably increases the risk of cardiovascular disease, and salt restriction lowers blood pressure and the risk of premature death.
Is there a relationship between changing body odour and Alzheimer's disease?
Loss of smell is a well-documented early sign of Alzheimer's disease, and changes in body odour are being investigated as a possible marker, but a clinically usable 'smell test' for Alzheimer's disease does not yet exist.
Does eating an avocado every day improve the diversity of your gut microbiome?
Eating an avocado every day likely increases the diversity of your gut bacteria, although the evidence comes primarily from people with overweight. If you have a healthy weight, the effect has not yet been demonstrated.
Does fasting reset your immune system?
Fasting lowers inflammatory markers and improves metabolic risk factors, but a true 'reset' of the immune system has not yet been firmly demonstrated. The strongest gains are in weight and blood pressure; for specific immune diseases it is still too early for conclusions.
Does fasting help your cells clean themselves up?
Fasting demonstrably increases the self-cleaning function of your cells, but watch out for muscle breakdown during prolonged fasting. Combine fasting periods with adequate protein intake and exercise for a better balance.