
Rule #5: Eliminate Processed Food (or Eat Real Food)
If you've read "The Healthy Indian Diet", you know easily digestible carbohydrates are associated with people becoming fatter. The explanation is straightforward: carbs breakdown into glucose in our intestines, and this glucose is absorbed into our bloodstream and causes levels of the hormone insulin to spike. Insulin then signals our fat cells to get fatter. So the higher our digestible carb intake, the higher our insulin levels are, and the likelier we are to get fat.
Easily digestible carbs -- particularly flour, sugar, and products made from them -- are the bulk of processed foods. By processed foods I mean fried flour products like sev and other dry nasto ("snack food"), chips, cookies, and Indian sweets, and also fast food (like McDonald's burger and fries) and street food (like pav bhaji).
These fried carbs, in addition to fast and bountiful amounts of glucose, give the body free radicals which are created when oils are heated in high temperatures. Free radicals lead to oxidative stress, which has been linked to inflammation generally and specifically to obesity.

Well, according to this insightful editorial in 2011, processed (or "ultraprocessed") foods, made possible thanks to food technologies, have ruined much of our natural food and made us fatter for many other reasons.
Those reasons are being high in calories, largely thanks to there being so many sweeteners. They are eaten in large portions because we do not get easily satisfied or full. They contain very little fiber, which helps in weight loss. (They also contain too little nutrition.) Also processed foods contain many chemicals, some of which some experts believe cause harmful hormonal effects on our bodies including making us fatter.
In contrast, real food -- unprocessed foods (like vegetables from your garden) or lightly processed foods (think yogurt from the store) -- is lower in calories, have more good fats and good carbs (such as fiber, a non-digestible carb), is more satisfying so we don't eat as much, and does not contain potentially harmful chemicals. So the Healthy Indian gets rid of all processed foods in the home and eats only real food to lose weight!