Article on exercise and weight loss

rubadub

The thermodynamics/calories thing is sort of right to a degree (but it is a good estimate so should be used IMO). I have studied physics in college and have calculated calories of substances. The definition of calories refers to its energy per gram. To calculate this you burn a fixed mass of a substance, this in turn heats a fixed mass of water. The energy required to raise a volume of water by a certain temperature is known so energy can be calculated from this.

So if you get 100g of chocolate and burn it and it heats 100ml of water from 20C to 60C, then it has raised by 40C. If you burn 100g of chicken and the temp goes from 20C to 40C then it is raised 20C. Therefore the chicken has 1/2 the calorific value of chocolate.

Calorific values are better applied to fuels, used in calculation for efficiencies of engines. e.g. 100ml of petrol should in theory raise say 100ml of water by 50C, but may be put in an inefficient burner and only raise it 25C, so its efficiency is only 50%.

Problem is your body is not burning/combusting fuel. Therefore the calorific values of food are only a rough guide. And since no better energy valuation system has been developed people use it. The weightwatcher point system is a different way of trying to estimate the energy humans get from food (I dont like it, figures too rounded and needs calculation). So a food with 2 points, might have more or less than 1/2 the calories of one with 4 points.

The calories system for humans does work fairly well, I use it, and other posters report good results. Some foods might give more energy, others less, but overall it seems to even out. If you went on some bizarre one food diet it might show up more. Alcohol for instance has been shown in studies not to put on the same fat per calorific value as sugar drinks. i.e. they had 2 test groups, both on the same food diets, one drinking maybe 500kcal alcohol, the other 500kcal sugar drinks. The alcohol group put on less weight.

I have noticed this empirically myself, I used to drink like a fish, and if I did the math of 3500kcal = 1lb fat, I should have been massive. I have seen this with many people I know. I know people who were 8pints a day consistently for months at a time, who ate well too, that is 3.2lb per week from booze alone. 2 guys I know were underweight while doing this.

If I drank 3500kcal of petrol or ate 3500kcal worth of fire lighters I would not expect to put on 1lb of fat!

In other threads people were saying this could be due to insulin spikes in the sugar drinkers etc. But that is just agreeing with the point, calories from different sources can have different effects on the body.

6 small meals a day is said to boost the metabolism. If I eat 6x500kcal meals rather than 2x1500kcal meals- the food being the exact same- then I will probably put on less fat doing it in 6 meals.

Calories are still the best way IMO. Other methods would require intensive research, e.g. feeding a lad 3000kcal of chocolate per day and measuring fat increase. But interaction between foods will also have effects, and timing of eating and portion size etc.

As mentioned it is easier to eat 1000kcal than burn it off. If I wanted a 1000kcal deficit I would find it far easier to eat 500kcal less, and exercise 500kcal more. This is probably better for your system too.

The article doesn’t mention the effect of muscle growth either, if I do 1 hour per week of weight training in the gym or cardio I can work off 500kcal. But with weights my body is growing new muscle, this uses calories on the off days, and increases my basal metabolism in the long run, since the new muscle requires energy just to be maintained. That is why I would highly recommend weight training for fat loss, and probably why I see most people on forums who successfully lost weight AND kept it off are doing lots of resistance training, some doing little or no cardio at all.

Pete4779

rubadub wrote: »

That is why I would highly recommend weight training for fat loss, and probably why I see most people on forums who successfully lost weight AND kept it off are doing lots of resistance training, some doing little or no cardio at all.

That's true, but the inherent unhealthy state of your heart and lungs with being overweight improves more with cardio than weights - so a combination of proper diet, cardio and weights all in the magic balance is probably the best combo.

For me, I always found that cycling like a mother****er was the best way to get weight off, but I think that it does develop some leg muscle through that anyway and also involves a lot of isometric (i think that's the correct type but not sure) muscle contraction with your arms.