Across the world, the concept of an ideal diet has been the focus of debates over the years. Numerous books have been written about diets. While Atkin’s diet, GM diet and Ornish diet are a few of the well-known diets of their time, with followers as well as critics, the notion of the ideal diet remains elusive. What seems to be right at one time gets proven wrong after a few years of medical research. In fact, it is hard for to differentiate good quality scientific research from shoddy or commercially biased work published with fanfare.
While discussing the topic of ideal diet, another key factor to consider is the vast economic, cultural and ethnic diversity among human beings who inhabit the planet, not to forget the climatic and geographic variability. What diet may seem ideal for Italy might not be feasible in China, for obvious reasons. Much depends on regional produce and local taste.
Is there really a holy grail when it comes to diet? The objective of this article is to summarize all available good-quality medical evidence to describe - in plain English – as to what could be the ideal diet in Kerala.
The Kerala scenario
Kerala is home to some discerning taste-buds that are, famously, resistant to change. Consider, for example, the Malayali tourist who goes to Switzerland on vacation and seeks out an Indian restaurant to dine at - a behaviour that might even seem counter-intuitive to a global citizen, who would expect a tourist to display an interest in local cuisine.
Kerala’s distinct culinary tradition, complete with some regional variation stemming from its ethnically diverse population, has been influenced by settlers coming from elsewhere in India, as well as ancient seafarers from foreign lands - all of whom have made significant cultural and gene-pool contributions over centuries.
It is therefore obvious that for Kerala, any proposed dietary modification should be customised to local culinary culture and tradition.
Within constraints, the following easy modifications in content and style will bring the Kerala diet closer to what can be termed an ideal diet at this time.
1. The ideal mix of carbohydrates, protein, vegetables and fruit for a meal is shown in the following diagram, based on a standard flat 9 inch dinner plate. This can be considered the basic template for a meal, and can be customized for individual family preference. Of note, this is a fixed portion, and buffet-style servings are to be avoided.
2. The Kerala lunch is almost universally rice-based. A large quantity of rice is typically consumed over lunch and dinner in the region. The quantity of rice needs to be cut down, ideally to 1-1.5 cups per meal for those doing light work. In fact, the rice must fit into a quarter of the 9 inch plate in the diagram above. Local alternatives to rice such as puttu, chapati, idly, upma, brown bread or dosa may be used. Those doing heavy manual work are eligible for larger portions.
3. The ideal type of rice would be parboiled red rice or Basmati, which have the lowest glycemic index (GI), a measure of how quickly glucose levels rise in blood after consuming a particular food. (Slower insulin rise, which means lower GI, is healthier) White rice is less preferred, as it is associated with diabetes mellitus.
4. Whole grain products are preferred over refined grain such as maida, as their glycemic index is low and are proven beyond doubt to be healthier for the body. High glycemic index foods increase the amount of body fat. Worldwide, current emphasis is on lowering carbohydrate intake, and for Kerala, this boils down to reducing rice consumption per meal, and going easy on sugar.
5. Sweeteners like high fructose corn syrup, a common ingredient of carbonated beverages, must be avoided. Fructose, unlike glucose, does not suppress the appetite centre - this leads to continuous eating without satiety. Besides, when compared to glucose, fructose is responsible for greater fat build-up in the liver and other parts of the body. This extra amount fat – in particular the abdominal visceral adipose tissue (also called pot belly) - contributes to insulin resistance, leading on to diabetes, hypertension, arthritis, polycystic ovaries, heart disease and even increases cancer risk.
6. The local perception that ‘fruit juice is healthy’ drives large-scale consumption of sucrose (cane sugar) and fructose (naturally occurring in ripe fruit). When a fruit is processed to make juice, its fibre content gets removed, releasing the sugars to be absorbed rapidly into the bloodstream, raising the glycemic index and triggering an insulin spike. Excess consumption of fruit juices and sugar-sweetened beverages has been linked with obesity and diabetes. Healthier alternatives to fruit juices/carbonated beverages are water, whole fruit, buttermilk or unsweetened lime juice.
7. Human beings, who were hunter-gatherers in their early days, clearly need to consume adequate fibre in their diet to ensure smooth functioning of their digestive tract. Legumes (beans family) and fruits are the richest source of dietary fibre. Vegetables and fruit servings must make up half the plate (potatoes are not counted as vegetables for this purpose due to high starch content). In addition to calories and dietary fibre, vegetables supply essential vitamins, minerals and antioxidants.
8. No discussion on diet is complete without addressing the safety and quality of the produce. The presence of pesticides in vegetables shipped to Kerala from outside of the state has been a matter of concern. The growing popularity of home-based vegetable farming in grow-bags has yielded safe and clean vegetables to a number of people in Kerala, and is in line with WHO’s World Health Day theme of 2015: “From Farm to Plate, Make Food Safe.”
9. A few nuts like almonds (badaam) or peanuts can be added to the menu, preferably without added salt or oil. Nuts supply healthy fats, vitamins and minerals. The total amount should not exceed 1/3 cup per day.
10. Salt intake must be kept at a minimum, particularly because the Kerala diet, by default, contains excess salt in the form of pickle and pappadam. The total recommended salt intake per day is no more than 6 g (one teaspoon) or the equivalent of 2300 mg of Sodium.
11. Typical of a sea-side region replete with rivers and lakes, most Keralites enjoy fish (seafood), which is heart-healthy. Among seafood, the healthiest choices are sardine (matthi), mackerel (ayala) and small fish, especially when traditionally baked in banana leaf or as curry. Fish is an excellent source of protein, vitamins, omega 3 fatty acids and calcium.
12. Lean meat such as breast of chicken is a healthy source of protein, although deep frying makes it nutritionally undesirable. Red meat, though popular in Kerala, has high saturated fat content, and is best avoided, or enjoyed in limited amounts.
13. Fish, egg or lean meat can be used to fill the quarter of the sample plate assigned to protein. Vegetarians may use chana, pulses, beans, nuts, tofu or paneer as alternative protein sources.
14. The updated US dietary guidelines state that foods like egg yolk that contain cholesterol, do not actually raise blood cholesterol. As saturated fats are the main dietary determinant of LDL cholesterol, and since eggs are low in saturated fat, egg yolk does not significantly raise blood cholesterol. (The new relaxed dietary guideline does not apply to red meat, though, as it contains saturated fat in addition to cholesterol).
15. When choosing the type of oil, it is useful to remember that more than the type of oil, it is the quantity consumed that is important. As oils are calorie-dense foods, least is best, given the abundance of oil in local cooking practices.
16. Oils containing saturated fat are widely regarded as unhealthy. Saffola, canola, sunflower oil and rice bran oil have the least amount of saturated fat among locally popular cooking oils. They contain a greater percentage of monounsaturated and polyunsaturated fats, which are considered healthier than saturated fat. Coconut oil and butter are rich in saturated fat. However, opinion is divided at this time whether coconut oil is less heart-healthy than other oils.
17. Fats that are solid at room temperature are called trans-fats. They are artificially created when manufacturers add hydrogen to vegetable oil – a process called hydrogenation. Trans-fats such as vanaspathy or ‘vegetable ghee’ increase the shelf life of foods, but are considered more harmful than saturated fats, as they raise LDL (‘bad cholesterol’) levels. Trans-fats, now banned in several developed countries, are relatively cheap – and extensively used in bakeries and roadside food stalls in Kerala. Although the ‘vegetable origin’ tag might misleadingly confer them an aura of innocence, the use of trans-fats must be discouraged.
18. In Kerala, where the majority of the tea-time snacks are deep-fried, the idea of healthy snacks needs to be actively popularised. Examples include kozhukkatta or ada (steamed rice cake with non-sweet filling), pulses, aval (pressed rice) products, brown bread sandwiches and wheat-dosa rolls with vegetable, egg or chicken filling.
19. Unfortunately, some of the most popular foods in Kerala such as the biriyani and the masala dosa, happen to be the unhealthiest. A single masala dosa with chutney and coffee can pack a whopping 600 calories and 10 grams of fat, about the same as a generous serving of chicken biriyani.
20. Last but not the least, the speed of eating deserves mention. More often than not, Keralites are in a hurry - whether on the road, during shopping or while at lunch. A meal often gets treated like a mere chore that needs to be solemnly completed in the shortest possible timeframe. Studies have shown that gulping food down in haste leads to consumption of greater amounts, and is a cause of weight gain. The reason for this is that the satiety centre in our brain takes about 20 minutes to respond to food signals sent up from the stomach.
The book ‘French Women Don’t Get Fat’ describes how French women relish their food, taking their own time to complete three full meals a day and still stay slim, compared to their American counterparts who consume the same kind of food, but at a faster speed. Slowing down during a meal to appreciate the aesthetic s, enjoy the aroma and then savour the taste would positively be a healthy dietary habit.
Abrupt changes in diet are seldom long-lasting. Making small changes in one’s diet based on the above facts, and holding creative discussions with children on what is healthy and unhealthy, is a realistic approach to generate a better dietary culture for the whole family.
(The author is a Senior Consultant Gastroenterologist and Deputy Medical Director, Sunrise Group of Hospitals)