Calorie/Weight Reduction == Less Energy?

[UncleFred]

Does being on a food-reduction/weight-loss program cause you to have less energy?

I’m in training for my annual physical. Mostly I’m cutting out my snacky foods and most alcohol, and seeing a slow but steady drop in weight. I’m by no means chubby to start with but don’t mind losing a few pounds.

On the down side, I’m 64 and play soccer 2-3 times a week and am sensing an overall reduction in stamina and energy since starting this reduction.

Cecil’s recent column update on fasting implies that when your calorie supply goes down, you drain some energy from your muscles before you start burning fat cells.

Is that what I’m seeing? Bummer if so.

[running_coach]

Basically, if you deplete your glycogen (sugar stored by your body), you have to depend on fat (and a small amount of protein) metabolism to provide energy. It’s a a slow process.That’s why runners who “hit the wall” in a marathon slow down so drastically.

Try increasing your carbs a bit. You really don’t want to be totally fat burning as this also increases the amount of protein used for energy. This decreases your muscle mass and will make it harder to maintain weight later.

[epbrown01]

@running_coach

Basically, if you deplete your glycogen (sugar stored by your body), you have to depend on fat (and a small amount of protein) metabolism to provide energy. It’s a a slow process.That’s why runners who “hit the wall” in a marathon slow down so drastically.

That’s true but there’s a reason people don’t “hit the wall” playing dodgeball or tiddlywinks or something - the average person’s got a pretty good supply of glycogen on hand. Typically people have an entire day’s supply (3000 kcals or so), and it takes more than missing your 3 p.m. Snickers to run out.

[running_coach]

Typical average storage is more like 400-500g. (1600-maybe 2000 kcal). Trained athletes have reached as high as 750g (rare).

If a calorie restricted diet is being followed with exercise, glycogen stores can near depletion. More so if a low carb diet is followed.

Even world class marathoners can have difficulty maintaining glycogen stores when training heavily.

[epbrown01]

@running_coach

Typical average storage is more like 400-500g. (1600-maybe 2000 kcal). Trained athletes have reached as high as 750g (rare).

If a calorie restricted diet is being followed with exercise, glycogen stores can near depletion. More so if a low carb diet is followed.

Even world class marathoners can have difficulty maintaining glycogen stores when training heavily.

While that’s possible, it seems unlikely given the OP’s description of his situation.

[DSeid]

Yeah, the op cutting out some snacky foods and alcohol is not going be enough to deplete glycogen stores to the point that would matter, let alone that would matter at a recreational soccer game level of acivity. And unless his baseline was a lot of snacky foods and alcohol it is not even likely to be that significant of a calorie deficit. This is either coincidental or psychological but not a result of trying to convince his doctor he is baseline thinner than he is. (Which reminds me of my wife forcing us to clean for the cleaning woman.)

That said individuals respond to energy deficits and surpluses differently. In normal weight individuals over-feeding results in an increase in activity energy expended (AEE), mainly in the category referred to as non-exercise activity thermogenesis (NEAT) which works to partially offset the increase of enrgy intake. They also decrease energy expended in response to underfeeding.

… As one example, Leibel et al. chronically over- or underfed human subjects to produce 10% changes from initial body mass, and did not restrict exercise (Leibel et al., 1995). Individuals compensated for this gain or loss both through resting metabolic rate and AEE. No differences were observed in compensation between non-obese and obese subjects, and the extent of compensation was greater than the predicted change in energy expenditure due to adjustments in body mass. In another experiment, Levine and colleagues overfed 16 sedentary, lean adults (both sexes) an extra 1000 kcal day–1 for 8 weeks, while restricting voluntary exercise. NEAT was estimated by subtracting of basal and postprandial energy expenditure from DEE, which was measured by DLW. Subjects displayed changes in NEAT that ranged from –98 to +692 kcal day–1, and 59% of the variation in fat gain could be statistically explained by the variation in NEAT (Levine et al., 1999).

The article reviews what is known about how that occurs but the short version is that it is not glycogen stores; it is instead an interplay between a variety of environmental and physiological stimuli with brain neuromodulators.

So if there really is a significant calorie deficit he could be one of those individuals who respond in that way as his brain attempts to defend what it has placed as his set-point by altering his percieved energy level.