Abstract

Since the initial scientific recommendations of 1970s on healthy dietary fat consumption, no population groups could really practice them with suitable menu formulations, till today. This is because of reasons like, difficulty in translating the recommendations into menu formulation with oils of unique natural compositions and also for the custom of using single edible oil for cooking. It was in this context of, constituting menu for balanced diets with fat in healthy format (e.g., different fats in equal amounts, with the polyunsaturated fatty acids in healthy ratios, like 4:1), continuing hypothetical, the authors attempted to derive a new menu table for a balanced diet with formatted fat using some of the routine food items of India. The approach was to construct a sample menu in tabular form for a balanced diet of 2000 Calories with fats in balance and a healthy ‘omega ratio’ (the omega -6 / omega-3 type fatty acid ratio). The methodology of tabulation was, arranging the food items in columns and their nutritive data in rows, till the development of the menu presented. Thus, the current work shows that it is possible to formulate a menu table for a balanced diet, with mathematically derived predictions on its nutritive qualities and format of fat. Though a predictive model, its methodology and format form essential grid molds for preparing metabolically targeted model diets for conditions of health and diseases, in the easiest way, with least wastage of resources. The tables of the workup can be used as tools or scales too, for the nutritive assessment of dietetic combinations, before and after preparing recipes. The contextual significance of the new workup is its highly predictable acceptability due to the familiar composition and cheaper budgetary load to the Indian population (i.e., traditional food items in near traditional quantities, on minimum expense).

1. Introduction

Following the discovery of saturated and unsaturated fatty acids in food items, nutritionists started searching their differential roles in human health and metabolism. It was from those searches, modern recommendations on dietary fat consumption started emerging since 1970s. ¹ Among these, the classic one (seen in maximum number of journals and textbooks) is the recommendation to consume saturated fatty acids (SAFA), mono unsaturated fatty acids (MUFA), and poly unsaturated fatty acids (PUFA) in equal proportion. ² Another authoritative recommendation in India is that of National Institute of Nutrition.

^{3, 4, 5} Recently, the recommendations on dietary fat consumption have gained significance in the field of life style diseases too – especially affecting the cardiovascular system, due to the presence of triglycerides and fatty acids in the interiors of atheromatous plaques.

Another point of significance regarding the triad of fat metabolism, diet composition and health is, human body’s inherent tendency to convert excess dietary carbohydrate and protein into fat stores.

⁶ So the latest clinical recommendation on dietary proximate principle consumption is to derive 50.00% - 60.00% of Calories from carbohydrates, 10.00 % - 14.00% Calories from proteins and the rest, definitely from fats, without crossing the limit of 30.00 %, for a day. That is, for meeting the requirement of 2000.00 Calories for a day, a person has to derive 1200.00 Calories (that is,60.00%) from 300.00g of carbohydrates, 240.00 Calories (that is,12.00%) from 60.00g of proteins and 560.00 Calories (that is,28.00%) from 62.25g of fats, without crossing their own categorical upper limits.

But beyond these basic recommendations, no precise guidelines are available for the people, for constituting balanced diets with appropriate menu combinations capable of providing adequate calories and sufficient amounts of other nutrients (essential amino acids ,protective nutrients),simultaneously keeping the fat consumption recommendations,. That is the menu combinations for a totally balanced diet continue to be hypothetical since 1970s.This is the situational significance of attempts to design menu combinations for totally balanced dietary formulations so that, the impact of the basic nutritional recommendations will be effected in the society widely. The authors’ attempt here is to propose a model menu combination of balanced diet with precise quantities of some of the locally available food items all over India. The most essential criterion for combining the items was their nutritive values for attaining the daily requirement targets on totaling (DRI - Dietary Reference Intake values of individual nutritive factors). The proposal of the model menu combination is essentially a categorized list of unprocessed food items in simple tabular form with their quantities in columns and nutritive values in rows. The categorization is into cereals, pulses, combination of fat sources and protective food items. This mode of presentation was selected for providing a better understanding on the process of translating basic nutrition recommendations to menu combination with mathematical precisions in quantities of food items and their nutritive values, and also for the easiness of precise interim nutritive evaluations at any point of the proposal buildup.

The methodologic significance of this workup is its resilience to provide grid molds for constituting menu formulations for metabolically differing conditions of health and diseases, with least wastage of time and resources in diet preparation. The significance of the proposed menu combination is its highly predictable acceptability due to the familiar composition and cheaper budgetary load to the Indian population (traditional food items in near traditional quantities, on minimum expense).

2. Materials and Methods

Screening a panel of 592 widely available food items in India and arranging them in columns and their nutritive data in rows for further calculations, constituted the general methodology of the workup.

As the first step of workup, since most of the natural food items being combinations of all the three proximate principles (carbohydrate, protein and fat), the authors sought items for their predominantly known content. Thus in the traditional way of selecting menu by the mankind, authors selected 300.00g of rice for carbohydrate and 60.00g of red gram dal, for the provision of protein. But, wheat and maize being two equally accepted cereals in India, the cereal quota (of 300.00g) was split into 150.00g rice,50.00g wheat (atta) and 100.00g maize. ^{7, 8, 9, 10} But the cereals being not full of carbohydrate, and red gram dal not full of protein (table 1- block A,I and sf.1), the combination could provide only 195.39g of carbohydrate and 34.19g of protein for the day (instead of the expected 300.00g and 60.00g,respectively), leaving a carbohydrate deficit of -104.61g and protein deficit of -25.81g, towards the daily requirements (the inherent carbohydrate and protein deficits of the cereals - pulse combination). On interpreting these deficits against the total structure of balanced menu formulation, were found to be essential, for accommodating the carbohydrate and protein moieties of the yet to be added items like the protective foods (for vitamins and minerals) and oil seeds (nuts).

The cereals - pulse combination contributed a categorical sum total of 2.44g fat (table 1- block B,I), and provided five essential amino acids in required amounts (histidine, threonine, tryptophan and the phenylalanine – tyrosine duo). Among the protective nutrients vitamin D, copper, molybdenum, and manganese were provided adequately (table 2, sf.2).

As the second step of workup, since none of the natural dietary sources of fat were found to contain SAFA, MUFA and PUFA in equal quantities with an internal omega ratio of the PUFA fraction as 4:1, authors tried to constitute a suitable combination of food sources with significant fat content, and make it part of the balanced menu formulation under trial, satisfying the recommendations.

Initially oils alone were tried, empirically selecting one SAFA predominant, one MUFA predominant and one PUFA predominant oil (here the coconut oil, rice bran oil and sesame oil, respectively) for a total quota of 80.00g, from the locality. But, on finding that mere oil combinations provided nothing to fill up the inherent carbohydrate and protein deficits of the cereals - pulse combination, trials were repeated with added oil seeds and milk. ^{11, 12, 13, 14, 15, 16, 17, 18} The particular combination given below (table 3) with inclusion of sesame seeds, sesame oil, rice bran oil, rice bran, olive oil, flaxseed, coconut, and milk, was thus derived, which provided around 9.00g of carbohydrate and 11.00g of protein towards the inherent carbohydrate and protein deficits of the cereals – pulse combination (table 1- block A I & II), still leaving around -96.00g of carbohydrate and -15.00g of protein deficits to be filled later ,for the day [the remaining inherent carbohydrate (-104.61g + 9.06g = -95.55g) and protein deficits (-25.81g + 11.11g = -14.70g) of the cereals – pulse combination, after addition of the fat sources] . The protein provided by the oil seeds and milk was of firstclass quality too (rich in essential amino acids).

The specific quantities of fat sources mentioned above were found out by, calculating the weight of each item capable of providing the required amount of particular fat type (e.g., MUFA) to the trial tabulation, along with other types. The specific quantity of each fat source was calculated by multiplying the ‘reciprocal of fraction value’ of a particular fat type (e.g., MUFA) in it, with its ‘required amount’ to the trial tabulation. That is, for getting ‘y’ grams of the particular fat type (e.g., MUFA) from 100.00gram of an oil containing its ‘x’ grams, the calculation was like ,100.00 divided by ‘x, into ‘y’. Then, for equalizing the gains of SAFA, MUFA and PUFA to the limitation of 20.75g, specific quantities of certain other locally available fat sources were also added (e.g., olive oil), adjusting the quantities of the previously added ones. Thus, similar to successful assembling of a jigsaw puzzle, repetition of specific quantity adjustments and addition of suitable new fat sources a few times, provided the combination of fat sources presented, obeying the classic fat consumption recommendations. For the purpose of availing adequate amount of omega-3 fatty acids, flaxseed was selected to the combination instead of flaxseed oil, due the comparatively wider availability of the former item all over India. Sesame seed was selected as the main firstclass protein providing fat source and milk was added as a customary food item of the farming Indian villagers.

The combination given above clearly showed, SAFA, MUFA and PUFA entities in equal quantities (20.75g each; with minor variations within a range of + 0.25g, due to the unique natural compositions of oils and because of rounding up of oil quantities to full figures or 0.50g levels).

[7-18] ⁷ At this point, the nutritive structure of fat sources in the combination revealed that, except the oil in flaxseed contained omega-6 fatty acids only, in their PUFA fractions, accounting for a total of 16.46g of omega-6 fatty acids in the combination (from the readings of the last column of table 3, sf.3).

So mathematically, for keeping the omega ratio as 4:1, rest of the PUFA compartment of the combination had to be filled with omega-3 fatty acids (that is 20.57 minus 16.46 = 4.11g of omega-3 fatty acids). In this combination the amount was provided by 7.60g of flaxseed oil present in 18.00g of flaxseed (because its 5.17g of PUFA fraction contains 4.11g of omega-3 and 1.06g of omega-6 fatty acids, according to the natural composition).Thus the ratio between 16.46g of omega-6 acids and 4.11g of omega-3 acids turned 4:1. The quantity of flaxseed was rounded to 18.00g, for the convenience of kitchen measurement too (9.00 teaspoons of flaxseed powder).

So, after adding the combination of fat sources, a carbohydrate deficit of -95.55g and protein deficit of -14.70g (the remaining inherent carbohydrate and protein deficits of the cereals – pulse combination, after the addition of fat sources) existed for accommodating the carbohydrate and protein moieties of the yet to be added protective foods. Till this moment, the cereals – pulse combination and combination of the fat sources had provided significant amount (32.62g –that is 85.84% of the dietary reference intake), of dietary fibers too (table 1- block A I, II and sf.1).

This combination of fat sources (table 2) had lifted up the thiamin, pyridoxine, phosphorus, magnesium and iron levels of the cereals – pulse combination well up to their daily adequacy levels, still leaving deficits for a few other protective nutrients and amino acids like lysine and the methionine – cysteine duo (1908.81mg instead of 2100mg and 903.39mg instead of 1050mg, respectively - table 4 and sf.4).

Now it became clear that, selection of the protective food items to the menu under formulation should be aimed at filling all the remaining nutrient deficits, but without providing significant amount of additional fat. But the formulation being for the people of a specified geographical area with low general income and own food culture, both the local availability and inherent menu customs also had to be considered. ^{20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31} It was thus the protective food items shown in the table (table 6) were selected (raw taro – leaves, Indian gooseberry, tomato green, cardamom, red cherries, chilli powder, raw zucchini green, ash gourd, ginger raw, coriander seed, coconut jaggery, and arrowroot flour) to the total combination. Another additional point of consideration was on, the inclusion of some of the locally available bulk forming food items of customary use in the Indian setup like the tomato green, ash gourd and raw zucchini green (for serving the purpose of ‘hunger killing’ with negligible calorie provision and so preventing the over ingestion of other high calorie foods).

The protective food items shown in table 1 on adding, provided sufficient carbohydrate and protein moieties (95.37g and 14.89g, respectively) to fill up the final carbohydrate and protein deficits of the day (remained after the addition of fat sources),with some residual deficits or nominal excess quantities of negligible significance in clinical nutrition (95.37g carbohydrate instead of 95.55g and 14.89g protein instead of 14.70g). They also filled up the dietary fiber deficiency, contributed 5.19g of excess fat and pulled up the levels of most of the protective nutrients, the methionine – cysteine duo and lysine to their daily target points (by 393.60mg and 165.92mg amino acids, respectively from the taro leaves, cherries and zucchini green- tables 1,5,6,7; also sf.1,5,6).

3. Results

^{32, 33} The predominantly vegetarian menu formulation provided adequate amounts of proximate principles, dietary fiber and essential amino acids, but presented partial deficiencies of certain protective nutrients like vitamin B12, sodium, chloride and complete deficiency of iodine and fluoride. ³⁴ None of the nutrients were provided more than their ‘tolerable upper levels’ (TUL), too (sf.2).

³⁵ Deficiencies of sodium and chloride are manageable with the use of currently recommended daily minimal quota of table salt – 4.4g/day (75meq).

Daily intake of body stored nutrients like the fat soluble vitamins is not mandatary. Still this formulation has provided adequate quantities of A, D, E, K vitamins, even in the setup of tropical location of India with adequate sun exposure sufficient for assuring the free availability of vitamin D.

Deficiency of another stored nutrient, vitamin B12 is inherent to diet combinations with food items predominantly of vegetable origin. Substitution of sesame seed in the formulation with extra milk (600.00g) or other dairy products (e.g., yogurt) or egg on other days can provide it adequately.

Iodine and fluoride are yet another set of stored nutrients. Since iodine content of vegetarian food items largely depends on the geographically variable iodine levels of the cultivation lands (depending on the sea proximity) and fluoride content on the fluoride levels of irrigating water of the locality, nutritive data with generalized applicability are not available for both of the nutrients and hence, quantitative adequacy of both with vegetarian diet formulations cannot be predicted. So, either inclusion of some sea products in diet or appropriate use of iodized salts are the two easily adoptable methods for assuring dietary iodine adequacy.

Availability of fluoride is primarily expected through the drinking water, rather than from food items. ³⁶ As a matter of fact, in most parts of India, the fluoride content of drinking water is about 0.50mg/L which is contextually optimal for preventing the manifestations of fluoride deficiency due to the habit of high water intake common to the tropical countries.

³⁷ The matter of two protective nutrients – chromium and molybdenum – deserve special mention here, because of their separate data source, since the earlier mentioned sources did not provide the required data. According to this source the current menu combination provides both the nutrients adequately, well below their TULs.

Though the excess 5.19g of invisible fat (around 1.00 teaspoonful) contributed by the protective food items (table 5), deserved negligible practical significance in clinical nutrition, for the perfection of the menu model it became essential to accommodate this into the initial fat combination of the model (table 3), and subsequent nutritive evaluation, for the sake of work completion. Out of the 5.19g, since the sum total of SAFA, MUFA and PUFA came to 4.01g (table 1 - block B, II and sf.1- block B, II), only the latter amount could be accommodated into the categorically designed table (table 8, sf.1- block B,I). The essential steps of accommodation were, reduction in the amounts of rice bran oil (from 20.00g to 16.00g) and flaxseed (from18.00g to 16.00g), with addition of 1.00g of safflower oil (table 8). On doing so, the new (modified) combination of fat sources again provided SAFA, MUFA and PUFA entities in equal amounts, and presented omega ratio of the PUFA compartment as 4:1 (16.77g of omega -6 fatty acids and 4.23g of omega -3 fatty acids; the minor variations within a range of + 0.25g are due to the unique natural compositions of oils and because of rounding up of oil quantities to full figures or 0.50g levels).

The nutritive impacts of these modifications were negligible because, all of the nutrients including essential amino acids already had attained adequacy levels with the initial combination of fat sources and protective food items continued to maintain their adequacy levels.

The final carbohydrate deficit fill did not show any significant change with the modification of the initial combination the fat sources (a mild hike in the nominal residual deficit from -0.18g to -0.21g). Similarly, the change in the final protein deficit fill was also practically negligible (a change from the previous nominal excess amount of +0.19g to a nominal residual deficit of – 0.17g: table 1 – block A bottom most lines). The final dietary fiber level showed a reduction of 0.54g (i.e.,540.00mg) from its surplus fraction of the previously established 56.13g, on modifying the initial combination of fat sources.

4. Discussion

Only balanced diet formulations can assure balanced nourishment to one’s body. But, eating with the same menu pattern on every day is not at all a comfortable practice in day to day human life. So there should be exchanges with nutritionally equivalent food items like the fish, egg, meat, or soya bean in place of nuts and replacement of one cereal with another one or combination of cereals within the limit of the total carbohydrate count of the day (here 300.00g); similarly pulses also should be frequently replaced with another ones or combination of pulses within the limit of their daily count (here 60.00g). But while recommending exchange of one food item for another one, the dietician should be cautious to assure adequate provision of the non-stored nutrients like water soluble vitamins (B and C) on every day, unlike the stored nutrients (e.g., fat soluble vitamins, vitamin B12, iodine) to be provided only days apart in a week. That is, ‘daily balancing’ is a must for nutrients which are not stored in our body. In clinical nutritional management, this custom of comprehensive balancing will provide sustained balanced nourishment at optimum market expenditure, in addition to the menu vividity.

Though the workup constitutes a model menu combination with mathematically predicted nutritional properties, can provide the essential guiding gridwork for preparing metabolically targeted dietetic models for clinical evaluation quite easily, cutting short of the wastages associated with trials of random dietetic models, to the minimum. Both the methodology of the formulation mentioned and its interim evaluation tables are, nutritive assessment tools also, for traditional as well as new menu formulations, before and after preparing recipes.

The final thing to remind the readers of this article is on the quantitative and qualitative variations in the components of balanced diet for persons differing in age, sex, physiological status (e. g., pregnancy) and the nature of physical work, and hence the necessity for selecting appropriate food items for constituting the required combinations.

5. Conclusions

Formulating balanced diets providing saturated, monounsaturated and polyunsaturated fats in proper quantities continues to be an under investigated area in nutrition biology. In this background the authors’ attempt show that, it is possible to propose a model menu combination in simple tabular form for constituting balanced diet obeying fat consumption recommendations, with specific quantities of certain locally available fat sources. The main steps of compilation of dietary fat sources keeping the consumption recommendations are initial empirical selection of some of the locally available oils with known composition and then equalization steps for the gains of SAFA, MUFA and PUFA to the limitation of 20.75g, keeping an eye on the omega-6 and omega-3 fatty acid content of the PUFA fractions. The equalization steps involve addition of specific quantities of other locally available fat sources and adjustments in the quantities of previously added ones, according to the mathematically derived interim inferences on the specific amounts of fat types contributed. The process of tabulating protective food items also essentially involves the steps of initial selection and then addition of new items, targeting on the daily adequacy levels of individual nutrients (DRIs), inferred from their interim totals on addition of each item. So the procedural workup during the proposal buildup for a model menu combination to constitute a totally balanced diet from the known database of locally available food items in simple tabular form, mainly involves mathematical calculations, and so the resultant models evolved are essentially, ‘simple mathematical models’ of menu for totally balanced diets.

The general method of proposal formulation is to start with the assessment of inherent carbohydrate and protein deficits of the cereals and pulses combination taken for the day’s calorie requirement from them, and then constitute the fat combination as mentioned above, without overfilling those deficits by the carbohydrate and protein moieties of the fat sources (like the sesame seed, flaxseed or milk). While constituting the combination of fat sources, inclusion of customary fat sources of the targeted food culture group (like grated coconut, milk etc.) and combining them with the other locally available dietary fat sources will increase the acceptability of the combination manyfold. Since the first step of workup (combining cereals and pulses) itself, interim nutritive evaluations of the formulation is mandatory, on addition of each food item (e.g., fat sources) till the final evaluation at the end of addition of the protective food items. At the very end, redesigning of combination of the fat sources and the final most nutritive assessment should also be done, with the incorporation of sum total of the saturated, monounsaturated and poly unsaturated fats from the protective food items (here 4.01g) to the initial fat combination - again keeping the fat consumption recommendations. But in clinical nutrition, these steps deserve significance only when the sum total of categorical fats from the protective foods is capable of quantitatively replacing any of the items (oils / oil content of fat sources) from the initial fat combination; otherwise these steps are for completion sake only.

Transmitting this knowledge or inclusion of already constituted balanced diet formulations with locally available food items, prepared by nutrition experts keeping in line with the present study, in the general health studies of school and college classes will enable the various regional populations of the world , for enjoying the benefits of healthy dietary fat consumption, with minimal family budget load. It will also help in constituting diet models for research works seeking the vital biological roles of omega-3 fatty acids with some locally available food items, instead of the commercially available omega-3 fatty acid capsules. It is possible to constitute similar balanced menu formulations according to the nutritional requirements of various pediatric age groups and pregnant women too, in the same method of this workup.

Acknowledgements

Funding: The study was carried out fully under the exchequer of the authors, from the beginning to completion.

Personal: Vasudevan Damodaran, former Professor & HOD of Biochemistry at Govt. Medical college, Thrissur, South India, pointed out in early nineties on the possibility of constituting balanced diets precisely obeying scientific fat consumption recommendations, with food items locally available in the Indian villages and also provided vital information regarding the nutritive aspects of native food items along with their background literature. Vasudevan Sankaran, then one of his subordinate selected the most suitable food items and developed the tabulation model for such a diet formulation presented as above , keeping all the recommendations with mathematical precision. Both the authors have made intellectual contributions, and have read, approved and agreed on the final manuscript, prepared for submission to the publisher.

Authors thank Dr. Prathap Somnath, Principal, Govt. Medical College, Thrissur, Dr. P.H. Prasad, Pathology professor and Sri. Wels. P.J., Chief librarian - Central library, of the same institution for their kind support extended towards the study. We also thank Smt. Reshma and Sri. Seby paul for providing their expertise in preparing this article for publication.

On Competing Interests: Both the authors declare that we have no competing interests, either financial or non-financial.

Supporting files: These are the reference data (nutrients per 100.00g of each food item), used for the interim and final nutritive assessments of the menu formulation presented in the article. These are cited in the article as sf.1,2,…etc., for the easiness of review process and better understanding on the subject, for the readers.

References