Is a calorie a calorie?
As a calorie (kcal), a unit of energy, the 2x200kcal in the pic are the same yes however, once ingested into the body they do differ (slightly). This is primarily down to the thermic effect of food (TEF), the influence of processing (IOP) & ultimately NET kcals. Therefore, taking the 2 examples, 270kcal of B&Js = 15g fat (135kcal), 30g carbs (120kcal), 4g protein (16kcal). 270kcal of chicken breast = 2.5g fat (22kcal), 1g carbs (4kcal), 61g protein (244kcal). As we know the TEF of food is 20-30% (let’s use 25%) for PRO, 5-10% (7.5%) for CHO & 0-3% (1.5%) for fat we can then calculate how much of a NET kcal is left for our body to use from the two
B&J = 2kcal burned from fat, 9kcal from CHO & 1kcal from PRO = 12kcal total thus the 270kcal goes to 258kcal
Chicken = 0.03kcal burned from fat, 0.75kcal from CHO & 61kcal from PRO = ~62kcal total thus the 270kcal goes to 208kcal
Furthermore, IOP also has an influence. Barr & Wright (2010) compared eating a “whole” food sandwich (multigrain bread & natural cheese) vs a processed one (white bread & processed cheeses) concluding that the whole food took 46.8% (576kj vs 310kj) more energy to digest than processed food. As B&J is a lot more processed than chicken breast, one could then argue that the difference between the two would be further increased as the B&J would take less energy to then use those 258kcal vs the chicken’s 208kcal
Summary? If you’re starting to stress about NET kcals then I think you are getting overly obsessed. The majority of weight loss studies show that total kcal intakes, not NET, are what’s most important for weight loss thus don’t be panicking however, there can be something said for the NET kcal in that if you comprise most of your kcals with junk and/or are digging for those last extra kcals on a diet, it may be beneficial to consume more “inefficient calories” aka your whole foods vs junk foods as they do use slightly more energy to get digested thus leading to a smaller NET calorie however, for the majority, just eat a mostly whole food diet (80:20) and stick to damn kcals & and save all this unnecessary stress