I have been using the below fasting protocol that I'd like to use for intermittent fasting -

Fast duration - Sunday night (10-11pm) to Tuesday morning (4:30am)

Consumed during fast - Only water (2-4L) and black sugarless tea/coffee (2-3 cups). Absolutely no other foods or beverages (no additional micro/macro nutrients) is taken during the fast duration.

Questions -

  1. Is this fasting protocol healthy? Any medical studies/literature explaining why it would be health/unhealthy?
  2. If the answer to #2 is negative, then wouldn't intermittent fasting in a paleo type of diet context be unhealthy as well? My understanding is that it'll involve similar type of fasting protocol but on alternate days.
  • Welcome to health SE :-). Unfortunately, we can't really say over the internet what might be causing your headaches, which is why personal medical questions are strictly off-topic here. This is a question for your doctor(s), i.e. your healthcare team.
    – Lucky
    Sep 28, 2016 at 13:06
  • 1
    Thank you. I have edited the question to remove personal medicine reference.
    – Achilles
    Sep 29, 2016 at 4:39
  • @Achilles, what exactly do you want to achieve with 1) intermittent fasting and 2) Paleo diet?
    – Jan
    Oct 4, 2016 at 12:16
  • @Jan My primary objective is intermittent water-only fasting. In addition to that, I'm researching paleo type of diet for non-fasting days. The main goal is health improvement via intermittent fasting with the understanding (maybe right or wrong) that intermittent fasting encourages zero calorie intake (hence water-only fasts) on fasting days.
    – Achilles
    Oct 4, 2016 at 12:28
  • @Achilles, I posted something below.
    – Jan
    Oct 4, 2016 at 13:19

3 Answers 3


You have to be sensible, losing weight is simple thermodynamics. If you consume less calories than you need, you will lose weight. Examine.com says it best:

What should I eat for weight loss?

Eat less. Different diets can make this easier, so pick whichever one best fits your lifestyle. Ultimately, you need to reduce your caloric intake.


Since prolonged fasting might increase heat expenditure, diets that manipulate fasting (Intermittent Fasting, Alternate Day Fasting) may have some benefits on the “calories out” side of things. Yet, even here, weight lost is mostly due to the fact that you control eating: It is much harder to overeat in 8 hours than in 16.

A good way to check that you aren't underfeeding yourself is to count calories and sum up per-week what you have eaten vs what your TDEE says you need. Pair that with your personal data for weight delta over the week and you can adjust your calorie intake appropriately.

Provided you are meeting your calorie intake sufficiently prior to the fast there is no reason why you would run into any issues during because you body has the energy it needs to get through.

The main benefit of your diet choice is most likely psychological, as you have picked those times because you believe/understand its easiest to fast then for you.

In summary,


  1. Provided you have a good grasp of your personal macro-nutritional and calorie needs, yes.
  2. The “paleo diet” (hunter-gatherer diet) is high in fats, high in proteins, and low in carbohydrates, its a means to assist weight loss through low carbohydrate intake, see answer to question 1.
  • Side comment on headaches: See your doctor to discuss your diet choices and make sure you are drinking enough water!
    – John
    Sep 29, 2016 at 9:20
  • Thank you. So, such water-only type of fasts don't have any particular health benefits other than weight loss?
    – Achilles
    Sep 30, 2016 at 2:18
  • Not any that are supported by good clinical trials!
    – John
    Oct 4, 2016 at 10:32

Here's one long review article with lots of references that mentions eventual health benefits of fasting:

Longo VD et al, 2014 Fasting: Molecular Mechanisms and Clinical Applications (PubMed Central)

I personally do not see fasting as a method to improve health, detoxify or lose weight but rather as something that can help spiritually. So, I do not want to comment those eventual health benefits - to me it's all vague and with insufficient evidence.

In a short article about fasting on WebMD, there is a statement that:

Fasting for a few days probably won't hurt most people who are healthy, provided they don't get dehydrated.


If you're fasting to lose weight, you may want to reconsider. The weight loss may not last after you finish fasting.

...both of which I agree with.

A good start to a weight loss diet is to adopt eating habits you actually intend to maintain life-long, so something what will become your new normal. If you think it has to be intermittent fasting, it is then your choice. From a limited evidence provided above, I do not think it is especially good or bad for physical health.

  • +1 Good point about the spirituality. I didn't think of it before, focusing only on the possible health benefits. Perhaps any habits one chooses need to be assessed from the spirituality aspect. Feb 23, 2019 at 13:32

According to the data that you have provided above here is something that will definitely help you out, and do try this out.

Assuming that you live in a part of the country which is very cold, that said you should consume tea and coffee with regular diet and not on the fasting day, coz the function of tea and coffee is to increase the blood pressure of a human being and usually in cold place having temperatures below 0-degree centigrade its a boon to the body.

Now the general functioning of the body is that it produces acid naturally and not the bases(alkaline substances) so you usually would have heard people that they are facing acidity problems and no one says anytime that they have basic/alkalinity problems, so when you drink tea/coffee on the day of the fast, you tend to catalyse the process of the formation of acid and you don't eat anything on the day of fasting, so make sure that you don't drink tea/coffee on the day of fasting. This will give you more headache feeling in the beginning but eventually will go away. If possible, please get rid of the habit of having caffeinated coffee/tea every day.

Also, soak Ocimum tenuiflorum, also known as Ocimum sanctum(holy basil) in water, put it in the water bottle for 2-3 hours and drink it during the day of the fast just like you are having normal drinking water.

Try this and do let me know about the results.

  • 1
    Could you please provide some references to your current claims (here is something that will definitely help you out, and do try this out)? BR Sep 28, 2016 at 14:17
  • Some high-quality bro-science there.
    – John
    Sep 29, 2016 at 8:33
  • Welcome to health SE. Aside from the fact that references are required here, I would like to stress that other users are not guinea pigs. You can't come here and say "try this and let me know about the results. It's unethical. In fact it might even be illegal.
    – Lucky
    Sep 30, 2016 at 6:22

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