First, bread and softdrinks are heavy in sugar, and sugar is the best immune system killer and cancer's favorite snack. Second, they are carbohydrates--too much of which will overwork your natural insulin. Well, in their case--because they worked hard at the construction site--a load up with carbs is understandable. But still, they had to be careful. Heavy work like that also needed protein and other nutrients.
Worse is that the softdrinks most of them were taking are known to be rich in caffeine. That made the combination worse--lots of sugar and caffeine. That will surely kill your kidneys, liver and pancreas.
And then, the cigarette.
No wonder many of them fall gravely ill when they reach old age--if they reach old age. While young, they may not feel the adverse effects yet so that everything seems to be okay. They learn about it later too late. That's why there is Choy's Cut--so you'd know it before it's too late.
If I were them, I'd opt for 2 or 3 bananas (or banana cue or fried banana wrap or "turon" which is often available in any localities), some bread, VitaMilk or Choco-Choco, or buy a bottle of water and mix in one or two sachets of Ovaltine and shake well. Better if they add one hard boiled egg. That's cheap health and fitness with middle income budget.