Tuberculosis (TB) remains a major public health threat globally. According to the global TB report 2022 there are 10.6 million cases and 1.7 million deaths reported in 2021(World Health Organization. Global Tuberculosis Report 2022, 2022). 1 India contributes to 26% of all cases but 32% of all deaths due to TB. The estimated number of deaths among TB patients, excluding HIV, is 4.93 lakhs (4.53-5.36 lakhs), an increase of 13% over 2019, the mortality rate being 37 per 100,000 (34-40 per 100,000) (World Health Organization. Global Tuberculosis Report 2022, 2022).1 The prevalence of malnutrition among TB patients ranges from 68.6 - 87% in Asians 2, 3 and 29 - 61% in African populations. 4, 5, 6, 7 Malnutrition is also common among the general Indian population, the prevalence of undernutrition (BMI<18.5 kg/m2) being 20.2% in men and 22.9% in women among adults aged 15–49 years 8. The other common nutritional deficiency found among the Indian population is anemia.9 Anemia is also common in TB patients. 10, 11

There is a bidirectional relationship between undernutrition and active tuberculosis.12 Active tuberculosis leads to weight loss and underweight is a known risk factor for the development of tuberculosis, either through reactivation of latent tuberculosis or through the development of progressive primary disease following infection. 12 In a patient with active TB, undernutrition is strongly associated with a wide range of adverse outcomes. 13 Poor nutritional status among patients with TB is known to be associated with a higher burden of disease in terms of longer duration of time to sputum conversion,14 treatment failure, higher risk of hepatotoxicity15, 16, 17 higher mortality 18, 19, 20, 21 and increased risk of reinfection/ recurrence.21

The dietary requirements for patients with TB can be considered in terms of their energy needs, macronutrients, and micronutrients. Patients with TB need more energy than the recommended dietary allowance (RDA) for the general population due to increased basal metabolite rate (BMR). 22 Inadequate intake of protein and calories can hinder the functions of host defense mechanisms that are essential for combating TB. Protein calorie malnutrition (PCM), characterized by inadequate intakes of both protein and total calories is common in TB patients. 23 Micronutrients are of great importance in the management of TB and their demand is increased by the intake of TB treatment drugs. Patients with active TB often suffer from a deficiency of micronutrients particularly iron, folate, vitamin D, and zinc. 5, 24, 25 Anti-TB drugs can also result in micronutrient deficiencies. For example, isoniazid administration can cause pyridoxine deficiency, and rifampicin can induce the metabolism of vitamin D, and lower its levels. Pyrazinamide, isoniazid, and rifampicin can lead to vitamin K deficiency,26 that may hinder the physiology of blood coagulation. Cerebral hemorrhage is documented in patients suffering from congenital tuberculosis due to vitamin K deficiency. 26 These are also known as hepatotoxic anti-tuberculosis drugs. But in most cases, especially in low- and middle-income countries, under nutrition is a result of patients not being able to purchase additional food because of economic hardship due to illness and loss of jobs or because of local food insecurity. 27, 28 Considering the financial burden and importance of increased nutrient intake, the national TB program in India has launched the Nikshay Poshan Yojana nationwide, a direct benefit transfer (DBT), where all the notified cases in the NIKSHAY portal receive Indian rupees (INR) 500 per month (~US$7) throughout the treatment for TB.

The nutritional status of TB patients is usually assessed using anthropometric measurements like body mass index (BMI) and mid-upper arm circumference (MUAC).29, 30, 31 Complete nutritional status assessment can be done through measurement of biochemical parameters, but they are more difficult to do and also costly. Though few studies have reported the levels of micronutrients in the serum samples of TB patients to determine nutritional deficiencies, 32, 33 literature from India on the same is limited. In a resource-constrained setting, consumption of nutrients can be known through the dietary intake of TB patients. History of diet obtained through 24-hour recall can provide information on the nutrients being consumed by the patients, which is a much easier way to assess the intake and can help in the decision-making on the requirements for additional supplements.

Among all the states and Union territories in India, Puducherry is a well-performing union territory, spending about 2.42% of GDP on health with the per capita health expenditure of about Rs.31,372. 34 Information on the deficiencies in the diets of TB patients can help in advocacy for the dietary supplementation of TB patients. Therefore, we aimed to examine the dietary intake of macro and micronutrients and associated factors among TB patients at the time of diagnosis to understand their intake patterns before they availed the benefits under the Nikshay Poshan Yojana.

The mean (SD) age of the participants was 42.4 (13.9) years ranging from 18 years to 75 years. Nearly three-fourths were males (73.4%), 71.1% were married and equal proportions were employed at the time of diagnosis. About 45.1% consumed alcohol, and 39.3% were smokers (Table 2).

The mean (SD) daily energy intake was 1414.3 (458.4 kcal) which is nearly 1000 kcal lower than the recommended daily allowance (RDA) of 2320 kcal. The intake of protein was 43.2 (30-60.3g), almost one-third lower than the RDA (60.0g) (Table 3). Micronutrients like iron, calcium, vitamin C, vitamin B12, and folic acid were also found to be lower than the RDA. Median (IQR) vitamin B12 and folic acid in their diet were 0.1 (0.00-0.14) mcg and 2.88 (0.00-5.76) mcg respectively.

On analysis of the factors associated with deficient intake of macronutrient among new sputum smear-positive patients, the prevalence of deficiency in energy and protein intake were higher in the middle-aged group with adjusted prevalence ratio APR of 1.08 (95% CI 0.97-1.20) and 1.40 (95% CI 1.11-1.76) among the elderly respectively as compared to younger adults (age 18-30 years). (Table 4)

Prevalence of deficiency in the intake of micronutrients like iron was 1% higher among the younger adults unadjusted prevalence ratio (UPR=1.01, 95% CI 0.90-1.14). The prevalence of deficient intake was also higher among unemployed (UPR=0.87, 95% CI 0.82-0.93) and was found to be statistically significant. (Table 5)

Table 5

Variables	N	Calcium	UPR (95% CI)	P-value	Iron	UPR (95% CI)	P-value	Vitamin C	UPR (95% CI)	P-value
		n (%)			n (%)			n (%)
Age group
18-30	36	33 (91.7)	1	1	33 (91.7)	1.01 (0.91-1.14)	0.777	28 (77.8)	1	1
31-60	122	118 (96.7)	1.05 (0.95-1.17)	0.311	110 (90.2)	1	1	91 (74.6)	1.04 (0.85-1.27)	0.68
>60	15	15 (100)	-	-	15 (100)	-	-	14 (93.3)	1.25 (1.05-1.48)	0.01
Gender
Female	46	43 (93.5)	1	1	46 (100)	-	-	39 (84.8)	1	1
Male	127	123 (96.9)	1.03 (0.95-1.12)	0.40	112 (88.2)	1	1	94 (74.0)	1.14 (0.97-1.34)	0.09
Occupation
Employed	124	118 (95.2)	1	1	109 (87.9)	1	1	94 (75.8)	1	1
Unemployed	49	48 (98.0)	1.02 (0.97-1.08)	0.31	49 (100)	0.87 (0.82-0.93)	0.00	39 (79.6)	1.04 (0.88-1.24)	0.58
Family size
More than 4	33	31 (93.9)	1	1	29 (87.9)	1	1	27 (81.8)	1.08 (0.89-1.30)	0.41
Up to 4	140	135 (96.4)	1.02 (0.93-1.12)	0.57	129 (92.1)	1.04 (0.91-1.20)	0.49	106 (75.7)	1	1
Ration Card
APL	108	104 (96.3)	1.00 (0.94-1.07)	0.77	99 (91.7)	1.00 (0.91-1.11)	0.84	83 (76.9)	1	1
BPL	65	62 (95.4)	1	1	59 (90.8)	1	1	50 (76.9)	1.00 (0.84-1.18)	0.99
Alcohol intake
No	95	91 (95.8)	1	1	88 (92.6)	1.03 (0.9-1.133)	0.509	55 (70.5)	1	1
Yes	78	75 (96.2)	1.00 (0.94-1.06)	0.90	70 (89.7)	1	1	78 (82.1)	1.16 (0.98-1.38)	0.08
Smoking status
No	105	101 (96.2)	1.00 (0.94-1.07)	0.847	92 (92.4)	1.02 (0.93-1.13)	0.555	83 (79.0)	1.07 (0.90-1.27)	0.41
Yes	68	65 (95.6)	1	1	61 (99.7)	1	1	50 (73.5)	1	1
Self-reported DM
Absent	9	87 (94.6)	1.03 (0.97-1.09)	0.31	85 (92.4)	1.02 (0.93-1.12)	0.60	68 (73.9)	1	1
Present	81	79 (97.5)	1	1	73 (90.1)	1	1	65 (80.2)	1.0 (0.92-1.27)	0.32
BMI
Underweight	72	70 (97.2)	1.05 (0.93-1.19)	0.37	68 (94.4)	1.12 (0.93-1.34)	0.20	52 (72.2)	1	1
Normal	76	73 (96.1)	1.04 (0.92-1.18)	0.49	69 (90.8)	1.08 (0.8-1.301)	0.41	60 (78.9)	1.09 (0.90-1.31)	0.34
Obese/Overweight	25	23 (92.0)	1	1	21 (84.0)	1	1	21 (84.0)	1.16 (0.93-1.45)	0.18

BPL below poverty line, APL above poverty line, 1=Reference range, UPR=Unadjusted prevalence ratio, APR=Adjusted prevalence ratio, DM=Diabetes Mellitus, BMI=Body Mass Index, Underweight <18.5 kg/m² ; Normal 18.5-22.9 kg/m2 ; Overweight 23-24.9 kg/m2; Obesity ≥25 kg/m2

The patients in our study belonged to the urban Puducherry and their dietary pattern was representative of all the pulmonary TB patients in this area.

Overall, TB patients in Puducherry were found to be having a low dietary intake of macro, and micro-nutrients. As tuberculosis has a devastating effect on the body's immunity and metabolism, the dietary intake of patients with TB should be monitored during ATT. Even though the government has taken initiatives like direct fund transfer to the patient's account, credited money may not be utilized for the right purpose. Therefore, dietary counseling along with vitamin supplementation in the right dosage can be advised and monitored.

The participants of the study are from South India, where daily food consumption has its nutritional benefits like consumption of fermented food like idly and dosa. Fermentation improves the probiotic properties, vitamins C, B, and B12 of the cooked food. The South Indian diet, which is primarily based on rice, includes a limited amount of protein, fibre, and micronutrients, but is high in carbohydrates. An adequate amount of these foods can make up for the deficit in calories and to an extent the micronutrients. However, protein intake needs to be improved through cheaper sources of protein like pulses, groundnuts, and if possible through intake of boiled eggs, steamed fish, and meat. Polished white rice which is consumed by the majority of south Indian population, can be replaced with red unhusked rice which is nutritious. Intake of fruits needs to be increased with seasonal and budget-friendly fruits like guavas, sweet lime, and bananas.

The method of preparing food and blending ingredients is more important than consuming nutritious food. Patients with TB should avoid eating more oily foods, especially deep-fried foods that are available in hotels. As calcium can impede the absorption of iron, calcium-rich food should not be taken together with iron-rich food. Meals can be taken as six small meals instead of three as nausea, vomiting, and loss of appetite are frequently reported among TB patients.

The authors thank the dietician Mrs. Leelavathy, Mrs. Saranya and medical social worker Mr. Thulasiraman for assisting in the 24hrs dietary calculation. The authors also thank Dr. Jeby Jose Olickal, Ph.D. Scholar for contributing and assisting in statistical analysis and all the participated enrolled in the study