Comment by romaaeterna | Hacker News Reader

Comment by romaaeterna | Hacker News Reader

I've found that calories-in/calories-out logic only gets you so far. It's foundationally true, of course, because energy is conserved, and we use all of the calories that we eat, with few exceptions, either for energy or for fat storage.

But exercise really helps. It changes what you want to eat first of all. Fat loss can be grueling or easy, depending on where your body wants to be, and exercise pushes it to the easier side.

Some of the non-calorie burning exercises have the biggest effects here. Weightlifting is almost pointless from a calorie perspective, but it really energizes weight loss. I assume that the hormonal effects are king.

Biking colossal distances is another thing that seems to lead to leaning out. In theory it should be possible just to eat through the calories burned biking, but in practice, it seems to shift the bias towards losing.

Also, the biggest problem with calories-in calories-out is that weight regain after a calorie deficit period -- even a long one -- seems to be almost a law of nature. The body seems to push extremely hard for regaining everything that has been starved off.

> Weightlifting is almost pointless from a calorie perspective

Maybe in terms of the energy you burn directly by lifting weights, but it raises your base metabolic rate significantly for quite some time after a workout. The extra muscle mass you built also raises your BMR in a longer lasting way. Especially when combined with interval training, weights are very effective.

Does it raise your BMR that much? What is that energy doing exactly? Does your body temperature increase? Do you move around more? You can't have energy going nowhere, of course. What other activities can drive the same? And what is the magnitude?

"The extra muscle mass you built also raises your BMR in a longer lasting way."

Unless you are talking about fantastic amounts of muscle mass here -- 10 pounds of muscle will only burn an extra 60-70 calories a day -- this oft mentioned factoid is unnoticeable in daily calorie expenditure.

It's hard to find good data on what the effects are in amongst all the bro-science articles, but I believe the raise in energy usage is due to the body repairing the muscles after the weights workout, so you'd see an increase in body heat generation (although the core temperature would stay the same, peripheral circulation would go up and skin temperature would rise a bit). HIIT is just good at hitting a lot of different muscle groups hard enough in a short amount of time to maximize the effect. It's not huge but several hours of increased passive energy burn does make a difference.

Also, 10 pounds of muscle isn't a fantastic amount to put on (depending on body size), especially if it's muscle that you're re-gaining rather than building for the first time. A few months of regular moderate weights work would build that much without pushing too hard. And again, passive energy burn is "free" and helps with gradual long-term weight loss.

Agree. Although, when I'm doing my working set of deadlifts (after a series of warm up ones) my whole body is by then heaving for air and on fire after the last rep.

It certainly gets the heart rate going. Now I don't do those every day, of course, but squats I do. Either as high rep/lower intensity warm up for other exercises, or low rep 5x5 heavy as a primary target of the day. They never fail to kick-start the body.

>I've found that calories-in/calories-out logic only gets you so far. It's foundationally true, of course, because energy is conserved, and we use all of the calories that we eat, with few exceptions, either for energy or for fat storage.

Unfortunately it is not true that we use all the calories that we eat in the same way, or that simple calories in/calories out is all that matters[0].

[0] https://www.youtube.com/watch?v=nhzV-J1h0do

To me the main issue with the calories in/out way of thinking is that while generally correct your body deals with different types of calories very differently. Obviously high quality protein and processed sugar cause very different hormonal responses in the body. The calories in/out way of thinking sort of brushes this under the rug.

The weight regain phenomenon you mention can be explained in part by the hormone ghrelin. I’m no nutritional scientist but from my understanding ghrelin is involved in meal initiation and is a driving factor in the weight regain after a period of weight loss. Conversely the hormone leptin acts to suppress food intake and would cause someone to lose weight after a brief period of weight gain. Together when functioning correctly these work to “stabilize” ones weight. Obese individuas are thought to be leptin resistant.

As you mention, hormonal effects are king and you want to take great care to not overly stress or break your body’s systems, for example, by becoming insulin or leptin resistant.

Reply on news.ycombinator.com