The Nidam al-Tayyibat system, presented by the Egyptian physician Diaa Al-Awadi, attracts contrasting opinions. According to the system, foods are divided into five frequency zones, from Green to Red. Its supporters see it as a clear and structuring framework; its critics highlight the absence of independent scientific validation. This page examines the arguments without settling the medical disagreements.
What is the Nidam al-Tayyibat and why is it debated?
The Nidam al-Tayyibat system classifies foods into five zones: Green, Yellow, Orange, Purple and Red. Each zone corresponds to a frequency of consumption, from daily for Green to exclusion for Red. According to the system, foods such as Dates (Green), Mango (Yellow), Tomato (Orange), Peanuts (Purple) and Chicken (Red) occupy different places. The debate arises from the nature of these classifications: they are presented as resulting from a medical approach, but they are not based on publicly accessible quantified publications.
According to the system, Green foods can be consumed daily, Yellow foods with a point of caution, Orange foods at an intermediate frequency, Purple foods rarely and Red foods never. This simple structure attracts many readers looking for dietary reference points. It avoids the complexity of nutritional tables and gives direct instructions. However, the very simplicity of the system is criticised: it does not provide detailed justifications for each exclusion and does not adapt to individual situations.
What do the system's supporters say?
Supporters of the system emphasise the distinction between “tayyib” foods (good, healthy) and “khabith” foods (impure, harmful). According to the system, this distinction is not based only on nutritional composition, but on an overall assessment of the food. The system highlights raw, natural products, such as Olive oil (Green), Green tea (Green), Bulgur (Green) or Sea fish (preferably grilled) (Green). It excludes processed products, such as Fizzy drinks and soft drinks (Red), Charcuterie (sausages, mortadella, pastrami) (Red) or Energy drinks (Red). This orientation partly aligns with public health recommendations that advise limiting sugary drinks and processed meats.
Another argument put forward in favour of the system is the emphasis on home cooking and natural fats. For example, Natural butter (Green) and Smen / ghee (clarified butter) (Green) are permitted, while Margarine (Red) is excluded. The system also permits White sugar (Green) in a limited quantity according to the system, which may be surprising, but it bans Artificial sweeteners (aspartame, sucralose, industrial stevia) (Red). Supporters consider that this approach favours a less industrial diet, closer to the culinary traditions of the Middle East and the Maghreb.
However, these choices are not demonstrated by controlled trials. The system has not published efficacy or safety data, according to the available information. Supporters often rely on personal experience or on the internal coherence of the classification, without independent review.
What are the main methodological criticisms?
Several methodological criticisms are made against the system. The first concerns the absence of peer-reviewed scientific publication. According to the system, the classification comes from its author's clinical experience, but no quantified document makes it possible to verify the zone criteria. The second criticism concerns the strong food exclusions: Cow's milk (Red), Eggs (Red), Pulses (broad beans, dried beans, peas, lentils, chickpeas) (Red) and Yoghurt (Red) are excluded, while many conventional nutrition reference points consider them useful foods. The third criticism concerns the lack of personalisation: the system gives fixed frequencies without taking into account age, sex, physical activity, medical conditions or medical treatments.
The question of White sugar (Green) is also discussed. The system admits it in the Green zone, which may conflict with the recommendations of many health authorities that call for reducing added sugars. Conversely, it excludes Orange (Red) or Melon (Red), whose value as fruits is often highlighted by conventional nutrition. These divergences do not mean that the system is wrong, but they indicate that the basis for its classification is not publicly justified.
Which foods are excluded, and what does conventional nutrition say?
The table below compares, as an indication, the zone according to the system and the position frequently encountered in conventional nutrition reference points. This comparison does not claim to settle the matter: it aims to show the differences and help the reader ask their own questions.
| Food | Zone according to the system | Conventional nutrition reference point |
|---|---|---|
| Chicken (Red) | Red | Often presented as a source of lean protein in many dietary reference points. |
| Pulses (broad beans, dried beans, peas, lentils, chickpeas) (Red) | Red | Frequently included as a source of plant protein and fibre in varied recommendations. |
| Yoghurt (Red) | Red | Often cited among fermented dairy products; its place varies according to the reference points. |
| White sugar (Green) | Green | Generally limited in public health reference points, consumed in moderation. |
| Olive oil (Green) | Green | Widely recognised as a fat of interest in the Mediterranean diet. |
| Tomato (Orange) | Orange | Eaten raw or cooked; the system prefers it cooked and in sauce. |
This table highlights points of convergence, such as olive oil, and significant divergences, such as chicken or pulses. According to the system, the latter are excluded, while conventional nutrition often encourages them. The reader should keep in mind that conventional nutrition is not a uniform block and that recommendations evolve.
What precautions for certain populations?
Before adopting such a restrictive food classification, certain categories of people should be particularly vigilant:
- Pregnant or breastfeeding women
- Children and adolescents
- Older people
- People with chronic diseases (diabetes, kidney failure, cardiovascular disease, liver disorder, eating disorder)
- People under medical treatment
The system does not provide a specific protocol for these populations, and excluding entire food groups may unbalance nutrient intake. For example, the system excludes Cow's milk (Red) and Yoghurt (Red), which are common sources of calcium and protein in many diets. It permits aged cheeses such as Cheddar (Green) or Parmesan (Green), but these do not necessarily replace all the functions of milk in the diet of a child or a pregnant woman. Similarly, the exclusion of Eggs (Red) may raise questions about the intake of certain nutrients, although the system permits other sources such as Lamb's liver (Green) or Sea fish (preferably grilled) (Green).
People under medical treatment, especially those taking anticoagulant medicines or treatments for diabetes, should be cautious: dietary changes can interact with treatments. A major dietary change without supervision can lead to imbalances or deficiencies. This article does not replace medical advice.
How can this system be evaluated without rejecting it outright?
It is possible to examine the Nidam al-Tayyibat critically without accepting or condemning it overall. Here are a few methodological points:
- Identify the foods the system permits and those it excludes, then compare them with available nutrition reference points.
- Check whether the exclusions concern foods you consume regularly and for which you have no obvious substitute.
- Consult a health professional before eliminating entire groups such as dairy products, pulses or eggs.
- Take into account your state of health, age, physical activity and any treatments.
- Do not follow a system solely on the basis of testimonials or unproven promises.
The system has points of interest, such as limiting sugary drinks, processed meats and many ultra-processed products. According to the system, Energy drinks (Red) and Fizzy drinks and soft drinks (Red) are excluded, which aligns with a large part of public health recommendations. But it also excludes foods that conventional nutrition often considers useful, such as Pulses (broad beans, dried beans, peas, lentils, chickpeas) (Red) or Orange (Red). These divergences must be weighed against your personal needs.
Frequently asked questions
Is the Nidam al-Tayyibat validated by scientific studies?
According to the available information, the system is not based on published, peer-reviewed clinical trials. It is presented by its author as an approach based on experience, but without verifiable quantified data. Independent scientific validation is lacking to date.
Is the system dangerous for health?
Any restrictive food system can present risks if applied without discernment. According to the system, certain common foods are excluded, which may lead to imbalances in some people. Medical advice is recommended before following this type of classification, especially in the case of a medical condition or treatment.
Why does the system exclude chicken and eggs?
According to the system, Chicken (Red) and Eggs (Red) are classified in the Red zone, that is to say, to be excluded. The precise reasons are not detailed in accessible publications, and this classification does not command consensus in conventional nutrition. It illustrates the fundamental divergence between the system and many dietary reference points.
Can this system be followed in the case of diabetes?
People with diabetes or with another chronic disease must consult their doctor before changing their diet. The system classifies certain sweet foods such as Dates (Green) or White sugar (Green), which may complicate blood sugar management. Without medical supervision, this type of diet is not recommended.
Are the food zones the same for children and adults?
The system does not provide a version differentiated by age, according to the available information. The same zones apply in principle to everyone, but the nutritional needs of children differ from those of adults. The exclusion of Cow's milk (Red) or Yoghurt (Red) in a child must receive particular attention and professional advice.
Further reading
- The Egyptian doctor's diet: who are we talking about?
- Khabith: what the word means, and what it excludes
- Tayyibat food zones: Green, Yellow, Orange, Purple, Red
- Vegetables allowed in the Tayyibat: the complete list
Disclaimer
This article does not replace medical advice. The following situations require professional advice before any dietary change:
- Pregnancy or breastfeeding
- Childhood and adolescence
- Chronic diseases (diabetes, kidney failure, cardiovascular disease, liver disorders, eating disorders)
- Ongoing medication
- Advanced age or frailty