Inadvertent Low Carb Dieting Question

Hypothetically, suppose that a person stops eating bread for a week for religious reasons. As a result, he ends up eating 25g less per day in carbohydrates. Assuming his total caloric intake and exercise levels remain the same, how much weight can he expect to lose in terms of glycogen and water?

Bread is not the only carb in a typical diet. Abstaining from bread may have made a dent in his carb intake, but probably a small one. And if his total calories stay the same, he’s probably eating other carbs in place of the bread, making the decrease quite negligible. His total carbs might even go up, who knows?

25 grams isn’t much; the “standard” 2,000 calorie diet assumes 300 grams of carbohydrates, plus total calorie intake stays the same, so I doubt there would be any noticeable difference; a normal diet assume that your body is also getting energy from fat, and fat will be broken down into glycogen if needed (proteins also, including those recycled from muscle breakdown).

Additionally, on plans such as Atkins, weight loss comes from your body going into ketosis, which won’t happen by skipping bread alone.

Thank you, Yankee. I was confusing glycogen and ketosis.

brazil84, the simple answer to your question is that if the calories and the exercise stay the same, he’s not going to lose anything.

Unless you’re eating Wonder Bread, 25g of bread is a little more than a slice, and I’ve seen “healthy” bread with more than that in one slice. If he’s used to having a couple slices of bread (toast) for breakfast, and a sandwich for lunch, it’s probably more like 80-100 grams that he’s planning on cutting out. If he’s used to having a bagel or a muffin, you can double that.

As noted above, if calorie intake remains the same, there won’t be any associated weight loss.

Not necessarily so. He won’t lose any fat but if he cut out enough carbs (making it up in protein and fats) he might lose some glycogen and with it some water weight. Over time the various “low carb” diets and other diets cause weight loss (and more importantly fat loss) primarily based on the degree of calorie deficit, yes. But there is a kick start on the scale (not in fat loss, on the scale) with low carb because the lack of carbs results in glycogen being burned and with its loss goes a fair amount of associated water. Even if the same energy went into more fat stores there would be some net weight loss. That’s why people tend to lose a fair amount of weight during the first week or so of a low carb diet, and why that same amount of weight comes back so fast when carbs are reintroduced.

25 grams less though? Probably not enough to do even that.

DSeid, thanks!