However, I don't know a lot in nutrition and I've got two questions about weight and calories.
Here are the questions:
# 1 : Let's say that I'm doing a diet on a regular basis and that I'm losing 300 g every day. If, one day, I decide to do an exception, and I eat a chocolate bar of 100 g, while continuing the diet as usual, which influence will it have on my weight loss ? As the chocolate weighs 100 g, at worst the risk is to lose only 200 g that day (300 g - 100 g of chocolate).
Although I think that a part of the chocolate will be eliminated anyway and that the weight gain should be a little less than 100 g.
# 2 : Let's say that I'm still doing the diet like the one above, and that the chocolate bar has 500 kcal. If, another day, I exceptionally decide to eat a part of cake which weighs 200 g and has 500 kcal, like the chocolate bar, will I gain (or will I not lose) maximum 100 g, (considering that the 100 g of chocolate has the same amount of calories than these 200 g of cake) ? In other words, is there a direct relation between calories and weight that I intend to lose ?
Your body isn't a calculator. The quality and composition of the food is very important, and somewhat separate from the energy value of the item. For me, at least, paying attention to the nutrition in the food first matters most, because 100 calories of cake vs. 100 calories of fried eggs are metabolized completely different by my system.
Might I recommend reading a resource like "Why We Get Fat" by Gary Taubes as a primer on this subject? Though somewhat simplified I think it might help you get out of a food weight/calorie arithmetic mindset, which doesn't work at all.
Though somewhat simplified I think it might help you get out of a food weight/calorie arithmetic mindset, which doesn't work at all.
Well, for some of us it does work pretty well, so I wouldn't say it's a useless concept. If I eat 1500 cals per day, regardless of nutrient composition, I can count on losing 4 to 5 pounds in a month.
To the OP: It's the caloric content, rather than the weight of a food, that determines the degree of weight loss or gain. If you consume 500 extra calories (beyond your energy requirements), you can expect a net gain of about 1/7 of a pound or 65 grams. Of course our bodies aren't entirely predictable and people vary in how they metabolize food, so your actual gain may be more or less than that. Still, the standard formula (3,500 cals = 1 pound) is as good a starting point as any.
I've got to agree with arctic mama. YOu may be able to the sums in theory but in practice, reality is unlikely to match your calculations.
First its unlikely that you would be losing 300g on a diet every day.
There are so many variables amongst individuals that we may all eat the same food, and do the same number of steps in a day (for example) but we will still find that different people will of the same height and weight will get different weightloss outcomes.
Such things include differences in personal metabolism. Differences in water retention. Differences in bowel movements.
So any calculation you do is just an estimate and reality could be quite different.
Re your second question, i think the direct relationship between weight and calories is fairly theoretical and approximate when played out in reality. In theory, yes when the variables are known, there would be a direct knowable relationship but since we never know the variables exactly, we can only guess at the relationship.
Nevertheless, generally the more we eat, the more we are likely to gain. The less we eat the more we can lose.
There is a relationship between caloric intake and body weight, but the relationship is far too complex to allow for consistently accurate predictions
Your body doesn't burn calories at a consistent rate. Not all foods are completely digested or digested at the same rate. What you eat can influence your metabolism and how much energy you burn. What you eat can also affect your immune system which can affect your metabolism. If you get sick, you may burn more or fewer calories than your average. Foods can affect hunger, which can affect calorie intake and thecability to stick to your food plan.
The food/weight relationship isn't one cause/effect relationship, it's thousands - so trying to predict or force your body into a precise and specific mathematical pattern is futile and frustrating.
You may or may not find calorie counting useful, but if you try to make it about the math, you'll drive yourself nuts.
I wanted to add that I've always been fascinated by the math, and for many years did drive myself crazy and off my food plan on many occasions trying to make my body "do the math."
I'm still fascinated by the math and the science that tries to get at the math, but to keep my sanity and my motivation, I can't try too hard to fit my body to the math.
Some interesting trends I've found either science or personal experiences (both my own and reported by others):
Many of us can lose more weight on low-carb than on the same calorie intake of higher carb (but you can't judge by the first couple weeks, because low-carb tends to flush a little extra water out of your system which isn't the weight loss that usually matters).
Some research finds this same difference, other studies find little difference. There's some evidence that the biggest difference is seen in insulin resistant folks and some diabetics, some of which find it hard to lose on even low calorie intake when not restricting carbs. In general, the more insulin resistant you are, the more the current math will overestimate your losses (at least on higher carb eating).
Some studies estimate that most folks, especially women lose about half what the current math predicts (meaning that some of the math equation(s) must be wrong or missing.
Yoyo dieting and metabolic issues such as diabetes, metabolic syndrome, PCOS, insulin resistance, low thyroid... can reduce metabolism, so that the math will overestimate lossed.
Some calories do not count, because they can't be completely digested, or in some cases at all.
Fiber calories can't be digested, at all, so none of the fiber calories count, and yet many calorie counters include them. This is misleading, because it makes 100 calories of broccoli seem functionally equivalent to 100 calories of oreo cookies.
Fiber isn't the only unuseable calorie. Some sugar alcohols (not really sugar or alcohol), resistant starch....
Even how well you chew your food can affect calorie absorption.
Many seeds have fibrous coatings that resist or even prevent digestion. Whole flax seed for example, has virtually no useable calories. The seeds have to be cracked or ground to provide calories and nutrients - if you swallow them whole, you might as well have swallowed sand.
We don't know enough about calorie math in the body to control weight loss by the math, but some of what we do learn can help us make the most of the math trends we do know.
Since I can eat more (volume and calorie- wise) with less hunger, and lose more consistently low-carb, whole-food, paleo eating gives me the best results (unfortunately it also tends to be more expensive and/or time consuming - but I'm working on overcoming that).
There's nothing wrong with using the known math estimates to make the most of your weight loss, but do not try to force or obsess over the math.
The only place a calorie is truly a calorie is in a bomb calorimeter in a lab. A Barbie doll has calories ... It's just a measure of energy content. How efficient the body will be at extracting that energy is definitely a variable. I'd call the 3500/# a decent starting guidepost; just be prepared to tweak for your individual eccentricities.
Arithmetic
It's just a measure of energy content. How efficient the body will be at extracting that energy is definitely a variable. I'd call the 3500/# a decent starting guidepost; just be prepared to tweak for your individual eccentricities.
