Lower Energy Expenditure With Processed VS. Whole Foods

Some of you may remember that long, long ago, people used to buy veggies, meat, rice, potatoes instead of ready-made chicken-risotto from the fridge. A recent study by Sadie et.al. (Sadie. 2010) shows that this might have been less convenient, but certainly more healthy. The scientists investigated the effect of food processing on postprandial energy expenditure and found:

Average energy expenditure for the WF [whole food] meal (137+/-14.1 kcal, 19.9% of meal energy) was significantly larger than for the PF [processed food] meal (73.1+/-10.2 kcal, 10.7% of meal energy).

While the perceived satiety of the 18 participants was comparable, figure 1 shows that the energy expenditure after whole food consumption was not only more pronounced it also lasted much longer than the one following the consumption of processed foods.

Figure 1: Postprandial increase in energy expenditure for whole foods (empty squares)
and processed food (filled triangles) (Sadie. 2010)

No wonder people who take up cooking and preparing their meals from fresh foods usually lose weight easily. They achieve the same satiety by effectively consuming less kcal. Additional effects such as a higher amount of vitamins and other healthy substances that may be lost in the course of industrial food processing will not only  potentate the weight loss effect, they will also improve your general health.