Protein, Zinc and Eating Disorders: The GAPS Discussion

The expanded GAPS eating-disorders chapter describes a cluster of nutrient shortages that develops in its restrictive-eating scenario. It names protein as the first deficiency after animal foods are removed, with severe zinc deficiency developing alongside it. The chapter then adds fat-soluble vitamins, B vitamins and magnesium to the picture.^[1]

Each nutrient has a different role. Protein supplies amino acids for growing tissue and many active molecules. Zinc participates in enzyme reactions. Fat, cholesterol, vitamins and minerals support their own processes. Keeping those roles distinct gives a clearer account than making protein and zinc responsible for every part of growth, repair and hormone production.

Why the Chapter Names Protein First

The eating-disorders chapter says plant foods are a poor source of protein for the human digestive system and describes animal foods, meat, fish, eggs and dairy, as providing the highest-quality, most digestible protein. In the scenario it presents, protein is the first deficiency to emerge after those foods are removed.^[1]

The 2020 book emphasizes animal foods as sources of protein and fat for tissue renewal. That is the nutritional emphasis behind its food pattern. A food label alone does not measure someone’s protein intake, digestion or nutrient status.^[2]

The older chapter connects inadequate protein with reduced capacity to build new tissue and make many active molecules. The later book also discusses cell renewal and the need for nourishing food. Hormones and neurotransmitters are chemically diverse, so that broad building-material discussion should not be read as saying every active molecule is made only from protein.^[1][2]

What the Chapter Says About Zinc

The same passage says severe zinc deficiency develops alongside the protein deficiency. It identifies meat, especially red meat, as the main dietary source in this discussion and says zinc participates in about 200 enzymatic reactions in the body.^[1]

Zinc participates in many enzyme reactions. It belongs alongside protein, fat and the other nutrients in the chapter’s account, rather than standing in for all of them. The eating-disorders overview places this discussion within the wider chapter.

Fat-Soluble Vitamins and B Vitamins

The expanded chapter says low-fat diets can produce deficiencies in vitamins A, D, E and K, affecting many metabolic processes and especially immune function. It separately says B-vitamin deficiencies emerge quickly when meat, eggs and other animal foods are removed.^[1]

The 2020 book reinforces the wider food pattern: animal foods supply protein and fats, and liver supplies most B vitamins along with vitamin A and other fat-soluble vitamins.^[2] These nutrients work together; the books do not reduce the eating-disorder mechanism to one isolated deficiency.

Magnesium and Processed Carbohydrates

The older chapter says vegetarian diets are predominantly carbohydrate-based and require substantial magnesium for carbohydrate digestion and metabolism, leading it to include magnesium in the deficiency pattern it describes.^[1]

The 2020 book gives a tighter current claim: it identifies daily consumption of processed carbohydrates as a cause of chronic magnesium deficiency.^[2] That distinction matters. The current framework does not treat every carbohydrate food as having the same effect.

Insulin and Fat Storage

The expanded chapter connects a carbohydrate-heavy vegetarian pattern with increased insulin production, a shift toward fat storage and difficulty losing weight. It also says many people gain weight after changing to a vegetarian diet; it does not present weight gain as a universal result.^[1]

The 2020 book defines the fat-storage mechanism more narrowly. In metabolic syndrome, insulin remains persistently high, and in that state the book calls insulin a master fat-storage hormone. It links this pattern to processed carbohydrates rather than claiming that a single serving of any carbohydrate automatically turns all food into body fat.^[2]

What Gut Tissue Renewal Requires

Protein is needed to build new tissue and cells, but the eating-disorders chapter does not describe gut repair as a protein-and-zinc process by itself. It says the gut lining constantly sheds and replaces cells, and that forming new cells requires healthy gut flora, nutrients and hormones. In the chapter’s scenario, all three are lacking.^[1]

The 2020 book gives gut flora the organizing role in this renewal. It says gut microbes orchestrate cell renewal, nourish intestinal cells and provide much of their energy. When that ecosystem is damaged, the intestinal cells can degenerate and lose digestive and absorptive function.^[2] The resulting poor digestion and absorption can deepen nutrient shortages, which is the cycle the older chapter describes.

Protein, Zinc and Hormone Production

The older eating-disorders chapter uses the term “hormonal exhaustion” and says protein, zinc, magnesium, fat-soluble vitamins and B vitamins are needed for hormone production. It then connects impaired hormone production with growth, menstrual cycles, sexual development, muscle tone, bones, energy, mood, concentration, sleep and skin.^[1]

The 2020 book distinguishes steroid hormones made from cholesterol, including estrogen, progesterone, testosterone and cortisol. It names animal protein, fats, zinc, fat-soluble vitamins and B vitamins within its account of cholesterol and sex-hormone production.^[2]

Protein and zinc therefore remain part of the nutrient supply for hormone production, but protein is not the sole raw material for every hormone. For the wider gut-brain sequence described in the chapter, read the proposed gut–brain sequence. The chapter’s vegetarian and vegan precursor argument is covered separately in the vegetarian and vegan patterns discussed in the chapter.

What the Zinc Trial Actually Tested

Birmingham and colleagues’ 1994 randomized, double-blind trial compared zinc gluconate with placebo in 35 female anorexia-nervosa inpatients. The zinc group had a faster rate of BMI increase during the trial. That is a specific measured outcome in an inpatient group, rather than proof that every person with an eating disorder has zinc deficiency or that zinc alone treats the whole condition.^[3]

A trial’s formulation, patient group and outcome matter. Do not turn the name of a nutrient into an individual supplement dose. Keep the actual product label and assessment findings with the clinician reviewing the question.

Make the Nutrient Question Specific

Bring the current food pattern, foods that have been removed, digestive symptoms and existing supplements into one record. Ask which shortages have actually been identified and how the nourishment plan will be reviewed. A list of symptoms or a restricted menu can raise questions without answering every one of them.

Frequently Asked Questions

Which Deficiency Does the Chapter Name First?

In the restrictive vegetarian or vegan scenario it presents, the chapter names protein first and says severe zinc deficiency develops at the same time.^[1]

Does the Source Say All Carbohydrates Cause Magnesium Deficiency?

The current 2020 book specifically names processed carbohydrates as the cause of chronic magnesium deficiency. It does not apply that statement equally to every carbohydrate food.^[2]

Are All Hormones Made from Protein?

No. The 2020 book says steroid hormones are made from cholesterol. Protein, fats, zinc, fat-soluble vitamins and B vitamins are among the nutrients it names for producing cholesterol and sex hormones.^[2]

Do Protein and Zinc Alone Repair the Gut Lining?

The eating-disorders chapter names healthy gut flora, nutrients and hormones together for new intestinal cells. The 2020 book says gut flora orchestrates cell renewal and nourishes those cells.^[1][2]

Your Next Step

Bring the actual food pattern, supplement labels and identified findings together before deciding what a nutrient name means for the person receiving care. My Care Team Log is listed in the WFLI Shop. A notebook can hold the same observations and questions.

References

1. Campbell-McBride N. Gut and Psychology Syndrome, expanded text represented by the second German edition (2015), “Essstörungen” (“Eating Disorders”). English paraphrases checked against that text; no English page numbers are implied. Nutrient sequence.
2. Campbell-McBride N. Gut and Physiology Syndrome (2020), gut-flora cell renewal, vegetarianism, hormones, magnesium and nutrient-dense animal foods.
3. Birmingham CL, Goldner EM, Bakan R. Controlled trial of zinc supplementation in anorexia nervosa. International Journal of Eating Disorders. 1994;15:251–255.