I am trying to talk a friend out of starting on a new cleanse / diet fad, which consists of some products with "concentrated amino acids" and some sugars and fats, and very little else. Apparently, the idea is that the body can produce whatever it needs from just amino acids and sugars/fats, and thus avoid "toxins". I convinced her to at least take vitamin and fiber supplements, but beyond that, she swears that this diet has all her body needs. Does it? If no, what consequences can this fad have for her health and why, so I can talk her out of it?
The appropriate diet must contain at least all essential nutrients:
- 9 amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, threonine, valine
- 2 fatty acids (alpha linolenic and linoleic acid)
- Vitamins: A, B1, B2, B3, B5, B6, folic acid, biotin, B12, choline, C, D, E and K
- Minerals: calcium, chromium, chloride, copper, iodine, iron, manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc
The Nationalacademies.org has tables of estimated average requirements for most nutrients.
The absence of essential nutrients, especially vitamin B1 and C, iron, potassium and zinc, can lead to nutrient deficiencies within a few months (MDEdge). Symptoms may include fatigue, mental changes, brittle nails, dermatitis, gum bleeding, etc.
Fiber is not an essential nutrient, but can greatly contribute to bowel regularity and can have other health benefits, such as lower blood glucose peaks after meals and better intestinal health.
Most of conventional dietary guides, such as Dietary Guidelines for Americans 2015, will tell you it is better to eat natural foods than supplements and extracts.
In the U.S., it is Food and Drug Administration (FDA) that dis/approves foods on the basis of the toxin content.
Some people believe that, apart from proven toxins, certain substances or foods are not good for them, based on how they feel after eating that food, for example. This may be an appropriate position, which can be judged by the presence or absence of peace in a given person, and may not be dis/proven by studies.
Anyone who claims that certain foods contain toxins needs to provide some reliable evidence about their harmful effects to be convincing. But then, it's all about what and whom someone believes.