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Nutritional and protein deficiencies

Short term deficiencies could have long-term consequences

This is one of the first reports that studies the relationship between food intake, nutrient adequacy of the diet and nutritional biological parameters measured before and in the short term (≤3 months) after GBP and AGB

Researchers from Paris, France, have reported that short term nutritional and protein deficiencies following gastric bypass (GBP) and adjustable gastric banding (AGB) could have long-term consequences. The paper, ‘Nutritional and Protein Deficienciesin the Short Term following Both Gastric Bypass and Gastric Banding, published in the journal PlosOne, suggests that patients should be monitored for protein intakes, both before and after the surgery, and that the consumption of protein-rich foods among a balanced diet should be recommended.

It is known that GBP can result in some malabsorption and therefore bypass patients are prescribed multivitamin and mineral supplements, whereas supplements are only recommended only when mineral and vitamin deficiencies are detected in AGB patients. Nevertheless, the researchers wanted to analyse food restriction effects on the nutritional adequacy of the diet, on macro- and micronutrient intake evolution in the short term post-GBP and AGB surgery.


Twenty-two females patients recruited in this prospective non-randomised study at the Obesity Unit of Pitié-Salpetrière Hospital, Institute of Cardiometabolism and Nutrition, ICAN, Paris, France, from July 2012. Medical history and clinical evaluation were obtained at baseline and during the follow-up at 1 (T1) and 3 months (T3). In addition, dietary data and nutrient intakes were recorded including foods and beverages consumed at breakfast, lunch, dinner or collation (occasion of consumption of light snacks). Patients were also asked to indicate multivitamin and mineral supplement use, specifying the product name and amount, including supplementation during two weeks before surgery (25(OH)-vitamin-D3 (once 4× 100,000 IU), thiamine (250 mg/day), and vitamin B12 (250μg/day).

For the GBP patients, multivitamin and mineral supplements (including Azinc “Forme et vitalité” (two capsules per day, containing 800 μg vitamin A, 1.4 mg thiamine, 200 μg folate, 1 μg vitamin B12, 120 mg vitamin C, 200 IU vitamin D, 8 mg iron, and 15 mg zinc), iron (2×80 mg/day), 25(OH)-vitamin-D3 (800 IU/day), and calcium (1,000 mg/day)) were started 15 days post-surgery and continued for the first year.

Nutrient intake adequacy for each patient was calculated using the PANDiet index, and the researchers used French nutritional recommendations for healthy adults or European Union values when specific recommendations were lacking. Blood samples were collected after an overnight fast to measure biochemical parameters using routine techniques. Vitamin and mineral deficiencies were defined as a result below the lower normal value. Secondary hyperparathyroidism was defined as an elevated PTH, above the high normal laboratory value. All measurements were conducted at baseline, T1 and T3 (except for 25(OH)-vitamin-D3 and PTH which were measured at baseline and six months after surgery) as proposed by a recent recommendations.


In total, 14 patients had a bypass and eight a band, and at baseline both groups had similar demographics and severity of obesity-related comorbidities, except for type-2 diabetes and glucose intolerance, which was significantly more prevalent in the GBP group. In addition, no differences were observed for energy, food, or macronutrient intakes between the two groups. The researchers reported that 85.7% of the patients were considered as under-reporters, with no significant difference between the two groups in terms of percentage of under-reporters and/or intensity of underreporting.

After GBP, the researchers noticed that starchy foods, meat and fish, and energy intakes decreased over time (significantly lower at T3 compared to baseline), whereas fruits and vegetables and dairy product intakes tended to decrease (T1) and then increase (T3). After AGB energy intakes and fruits and vegetables tended to decrease over time, whereas meat and fish, starchy foods and dairy products intakes tended to decrease at (T1) and then stabilise at (T3).

“In both groups, food intake caloric reduction involved all three meals without significant increase in collation energy intake, thus demonstrating that patients followed the prescribed dietary advice,” the researchers write. “Furthermore, patients displayed a significant 2-fold decrease in food ingestion speed in both surgical models (15±6 vs. 6.3±3.2 kcal/min at baseline and T3 respectively) in agreement with clinical advice to chew their food slowly after surgery to improve food tolerance. Likewise, vomiting or digestive discomfort was scarce in this cohort.”

There was a decrease in total protein intake in both groups and was more noted in the  GBP group, compared to the AGB group, resulting in significantly lower total protein intake in the GBP group at T1 and T3. However, the consumption of protein was below the recommended value of 60g/day for 88 to 100% of the patients post-surgery. After GBP, total fat and saturated fatty acids (SFA) significantly increased at T1 and tended to decrease at T3 whereas total carbohydrates significantly decreased at T1 and tended to increase at T3. After AGB, total fat and SFA tended to increase during the follow-up whereas total carbohydrates tended to decrease during the follow-up. In both surgical models, carbohydrate consumption was mainly composed of sugars rather than starches.

Nutrients and diet

At baseline, neither the PANDiet scores nor the probabilities of nutrient adequacy differed between the two groups. Low probabilities of adequacy for protein were observed in both groups as compared to the French adult population. After GBP, the percentage of patients taking the prescribed systematic multivitamin and mineral supplements (as seen in the food diary reports) significantly increased, from baseline to T3: 7 versus 86% for GBP as expected by the recommendations.

Due to this supplementation, the global nutrient adequacy of the diet did not drop but rather stabilised along the follow-up (PANDiet score and Adequacy sub-score were not significantly different at all-time points). Furthermore, the probabilities of adequacy for vitamins C, D and E were improved. Of note, when the global nutrient adequacy of the diet was calculated without taking into account the prescribed supplementation, the PANDiet score and the Adequacy sub-score significantly decreased at T1 and T3 as compared to baseline.


The researchers explain the decrease through the significantly lower probabilities of adequacy for protein, fibre, zinc, potassium and iron, but also by non-significant trends of lower probabilities of adequacy for the other micronutrients. Importantly, since the prescribed supplementation neither contains protein, fibre, nor phosphorus, lower probabilities of adequacy for these nutrients were observed at T3 compared to baseline.

After AGB, only patients with deficiency were prescribed with multivitamin and mineral supplements. Therefore, the percentage of patients taking these supplementations was lower than the GBP group reaching 13 and 25% at T1 and T3, respectively. As a result, the decrease of the global nutrient adequacy of the diet was similar to that of patients from GBP when not taking into account the prescribed supplementation (trends not reaching significance). There was no significant difference of the nutrient adequacy of the diet between the two surgical models at baseline, T1 and T3, with and without taking into account the prescribed supplementation.

Nutritional deficiencies

At baseline, none of the metabolic and nutritional parameters were different between the two groups, except for the concentrations of 25(OH) vitamin D3 and erythrocyte folate which were lower in the AGB group (Table 1). More than 70% of patients from both groups presented 25(OH)-vitamin-D3 deficiency as seen by serum concentrations below 30 ng/ml (Table 4) with subsequent secondary hyperparathyroidism in 45% of the patients, showing major deficiency in this population. Furthermore, 27% of the patients displayed authentic iron deficiency, as seen by low level of ferritin (below the normal range (N) for premenopausal women, 30≤N≤300μg/l) which translated into reduced erythrocyte globular volume in 18% of the patients (mean volume 76.5±1.3μm3). These results led to the prescription of iron supplementation to treat this biologically proven deficiency. Medical and morphological examination did not display any signs of bleeding. Similarly, 23% of the patients displayed thiamine deficiency (as seen with thiamine concentrations below the normal range; [126–250 nmol/l]), which was consistent with a low probability of adequacy for thiamine.

Table 1: Metabolic and nutritional parameters according the surgical models at baseline and one and three months

After surgery, as a consequence of low protein intake, prealbumin concentration significantly decreased during the follow-up, reaching the same level after both surgeries at T3 (Table 4). Subsequently, at T3, around 60% of the patients from both groups presented mild protein depletion as shown by prealbumin concentration below the normal range of 0.2g/l. More than 40% of patients from both groups presented risk of mild protein malnutrition as shown by albumin concentration below the normal value of 37g/l (Table 4). This low grade inflammation significantly decreased in the short term with a mean CRP value of 3.9±3.2 (p=0.001).

Patients who underwent GBP are systematically supplemented with 25(OH)-vitamin-D3, thus this nutrient intake was increased largely above the recommended daily intake. However, no toxicity was seen since calcium serum levels remained within the normal range during the follow-up (Table 4). 25(OH)-vitamin-D3 serum concentrations evaluated at six months displayed that this large supplementation only resulted in vitamin D normalisation after GBP but not after AGB group. These results are consistent with the malabsorption component of GBP. Conversely, since patients who underwent AGB are supplemented with vitamin D only if a deficiency is seen upon biological evaluation, the probability of adequacy for vitamin D was not improved and the 25(OH)-vitamin-D3 serum concentrations remained below the normal range six months after the surgery.

Regarding iron, the systematic supplementation prescribed to GBP patients induced an increase in the probability of adequacy which reached the level of a reference population. The measured iron daily intake reached 6 fold that of the recommended daily intake, however remaining below toxic values as indicated by normal blood iron and ferritin level. This supplementation effectively treated patients who presented discrete anaemia at baseline. Conversely, since patients who underwent AGB are supplemented with iron only if needed, the probability of adequacy for iron was not improved. After AGB, two patients needed iron supplementation (same doses as GBP), among whom one demonstrated persistent iron deficiency suggesting that the number of patients with iron deficiency increased along the follow. Of note, none of these patients developed anaemia at the time of follow-up.

“To the best of our knowledge, this is one of the first reports that studies the relationship between food intake, nutrient adequacy of the diet and nutritional biological parameters measured before and in the short term (≤3 months) after GBP and AGB,” the researchers write. “In this study where the patients had similar clinical characteristics at baseline (except for type-2 diabetes and glucose intolerance prevalence), our main findings are: (i) protein intake significantly decreases after both surgeries, inducing mild protein depletion in 59% of all the patients at T3, (ii) AGB is not harmless, since it significantly reduces food consumption, leading to biologically proven vitamin and mineral deficiencies. This suggests that a systematic multivitamin and mineral supplementation could be required at least in the short term, (iii) systematic multivitamin and mineral supplementation after GBP seems to prevent these early nutritional deficiencies.”

“In conclusion, this study combines a thorough quantitative evaluation of food intakes in terms of macro and more importantly micronutrients, adequacy score and serum concentrations of vitamins and minerals…our results suggest that candidates to AGB might benefit from systematic multivitamin and mineral supplementation,” they conclude.

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