This one is the strawman argument that I think irks me the most. Because, ultimately, this argument is meaningless when it comes to the fact that our bodies MUST obey the First Law of Thermo ... and don't go on with the BWBS.
Some claim the calorie levels reported for most foods are off by as much as 30%. This could well be true - especially for things like hamburger. It's also been shown that we absorb fewer calories from whole unprocessed foods than from highly processed/refined. Add microflora to the mix and we extract more or less of the same food than our neighbor. Also, different fats, carbs and proteins actually have differing energy density. For example sucrose and starch yield slightly different calories/g (if memory serves sucrose is slightly less than 4, starch slightly more than 4).
But does that last paragraph prevent us from getting a pretty good idea of CI? I'd say not. For one, it's average intake over time that's important, not that I ate the 100 cal cup of fauxgurt vs. the 80 cal cup. For another, it's the amounts of food in the end, not the exact calories. So, for example, if I decide to go participate in some study where I eat my usual foods for a month and some poor schmo is tasked with weighing and measuring all foods provided - uneaten portions, one can gauge my intake pretty well. Perhaps I eat 250 cal/day less than one other study participant or 250 more than another. So? Also, perhaps the three of us actually "intake" the same number of calories in the end b/c of our digestive efficiencies. Does it really matter to me, and a CICO approach to bodyweight whether +250-gal gets to eat more than me? In the "it's not fair" department, I suppose ...
Do the caloric variations of foods matter? Again, I'd say not in that these fluctuations about exact caloric content will be in both directions. I may buy an 85% fat ground beef that's only 82% fat one day, actually 88% fat another. I could, perhaps, take advantage of this by, say, replacing all 9 cal/gram long chain fatty acids with MCT Oil containing something like only 8 cal/gram.
OK so ...
How about calories out? In the inaugural episode of his new podcast, Low Carb Conversations, Jimmy's co-host Mindy tells the tale of trying to lose some weight she'd regained in an OCD-fashion. She used one of those BodyBuggs to measure her CO and was diligently monitoring CI. According to her calculations, she should have been losing weight hand over fist but she didn't lose weight. Of course one has to ignore her little inconvenient fact that she once lost almost 100 lbs with a traditional CICO approach (aka the "wrong way" because somehow she must have been a pile of goo since you only lose muscle that way ... ). But since switching to LC has Mindy lost that BB? I'm willing to bet that if she continued her tracking with low carb, she'd be showing a CICO deficit during the period she lost weight. But back to that BB for a moment. There are all sorts of problems with such devices - they exemplify the real problem with measuring ACTUAL energy expenditure. The most accurate way to do that is in a metabolic chamber - aka a human bomb calorimeter - all other such devices use various formulas considering movement, heart rate, skin temperature, etc. Nevermind that you can get different readings wearing one on different places on one's body, etc., or that these devices notoriously under or overestimate the caloric expenditure of certain movements. My point? Relying on the BB for an accurate calculation is the problem here. It was obviously overestimating Mindy's CO if she wasn't in energy deficit. Rather than cutting intake by an additional 500 cal/day, Mindy accepted the dubious accuracy of CO and figured something else must be going on here. Good luck with that.
Obviously CO is complicated. Basal metabolism is said to account for around 60% of BMR in most people. Many fidgety folk have high NEAT (non-exercise activity), some have higher average body temperatures (I'm so never going to be a Matt Stone hot chick!), etc. Some burn less fuel doing the exact same activity when they're reduced obese vs. before they got that way at the same weight. We have little control over these factors. But we can exercise more, deliberately move more. And contrary to what Gary Taubes tells us, exercise tends to, if anything, increase our activity the rest of the day, not cause us to lie around more.
CICO based approaches ALWAYS work. EVERY time they are applied in controlled circumstances. Measure TDEE and accurately assess intake and if a person is in energy deficit, they lose fat or vice versa.
Unfortunately many of us, women in particular, have been lied to regarding caloric needs. Even the official Atkins site , and if memory serves The New Atkins book, acknowledge the role of calories in weight loss.
3. BE SENSIBLE, NOT OBSESSIVE, ABOUT PORTIONS. There’s no need to count calories on Atkins, but we do ask that you use a little common sense. You probably could guess that too many calories will slow down your weight loss, but here’s a surprise—too few will slow down your metabolism and slow weight loss. You only need worry about calories if, despite following Atkins to the letter, you cannot lose weight. Then a calorie reality check may be in order. Depending upon your height, age and metabolism, you may need to play with the following calorie ranges to lose weight:
- Women: 1,500–1,800 calories a day.
- Men: 1,800–2,200 calories per day
Please note: Those are for weight LOSS! Perhaps for the morbidly obese, but not for the merely somewhat overweight. For women, 1500-1800 cal/day is maintenance levels. The 1500 cal/day low is the average intake for American women in the 70's. And you know what coincides with the obesity epidemic of the 80's? Average intake increased to around 1800 cal/day.
Whatever diet you choose to lose weight, it must create a sustained energy deficit. To maintain the magnitude of that deficit, you're probably going to have to increase activity to increase CO, because:
- At some point it's just impossible to eat any less and still enjoy one's life. And,
- Increasing activity helps maintain TDEE even when RMR is inevitably dialed down
If you're monitoring CICO with logging and a BB-like device, supposedly in a deficit, and still not losing weight ... there's something wrong with how you're monitoring!
- For CI: Estimating vs. actually weighing and measuring is a huge issue here ... I submit this is more likely the suspect for high fat eaters because of the high caloric density. Whether it's free-pouring coffee cream or dolloping out sour cream, it's easy to underestimate by at least 50 if not 100%!
- For CO: Remember, those readouts are ultimately estimates based on a formula. Whatever you're doing, perhaps (presuming you're not exercising for hours on a daily basis) a bit longer is all that's needed.