瘦身绝技：別锻炼。別吃午飯。
2020-02-12 17:32阅读：
加州大學（伯克利）物理系教授Richard Muller
在自己的身上做了实验，并发表了一篇关于如何减肥的学术文章。由于文章的影响太大，他只好改写成了非物理学家也能读懂的科普文章。
结论是：別锻炼，別吃午飯。
文中妙语连珠。
What is the best way to reduce belly fat and flatten your
stomach?
Richard Muller, Prof Physics, UC Berkeley, author 'Now, The Physics
of Time'
Answered March 4, 2017 · Featured on HuffPost, Forbes and The
Independent · Author has 2.4kanswers and 182.8m answer views
Originally Answered: What is the best way to reduce belly fat and
overall weight?
Eat less. There’s no real alternative.
Most dieters are so concerned about second-order effects, such as
daily fluctuations in weight and changes in metabolism, that they
lose track of the first law of thermodynamics: conservation of
energy.
Want to lose a pound of fat? You can work it off by hiking to the
top of a 2,500-story building. Or by running 60 miles. Or by
spending 7 hours cleaning animal stalls. (It is amazing what
scientists have actually measured. This last example is tabulated
in the
book Exercise Physiology by G. Brooks and T. Fahey.)
Exercise is a very difficult way to lose weight. Here's a rule of
thumb: exercise very hard for one hour (swimming, running, or
racquetball)– and you'll lose about one ounce of fat. Light
exercise for an hour (gardening, baseball, or golf) will lose you a
third of an ounce. That number is small because fat is a very
energy-dense substance: it packs about 4,000 food calories per
pound, the same as gasoline, and 15 times as much as in TNT.
If you run for an hour, you'll lose that ounce of fat and also a
pound or two of water. By the next day, when you've replenished the
water, you might think, 'the weight came right back!' But you'd be
wrong -- you really did lose an ounce. It is hard to notice, unless
you keep running every day for a month or more, and don't reward
yourself after each run with a cookie.
There is a much easier way to lose weight, as we can learn from the
first law of thermodynamics. Eat less.
A reasonable daily diet for an adult is 2,000 food calories. That's
8.36 megajoules per day, or about 100 joules per second -- in other
words, 100 watts. Most of that ends up as heat, so you warm a room
as much as a bright light bulb. Cut your consumption by 600
calories per day and you'll lose a pound of fat every week. Most
diet experts consider that a reasonable goal. Don't drop below
1,000 calories per day, or you might get lethargic. But at 1,400
calories per day, you can easily maintain an active life.
Of course, there is a catch. You'll be hungry.
It's not real hunger–not like the painful hunger of starving people
in impoverished countries. It's more of a mild ache, or an itch
that you mustn't scratch. To be popular, a diet must somehow cope
with this hunger. Weight Watchers does it with peer support. The
food pyramid does it by encouraging you to eat unlimited celery.
Some high-fat diets satisfy all your old cravings -- and figure
you'll eventually cut back the butter you put on your bacon.
I put theory into practice. In 2003, I had once again grown out of
my belt. I wasn't grossly overweight: 205 pounds in a six-foot,
one-inch body. That wouldn't be bad for a football player, but I'm
59 years old, and the excess pounds weren't in muscle. I had gained
a pound a year for several decades. I felt heavy and old. I decided
to try conservation of energy. I gave up lunch and snacks.
How to cope with the hunger? I attempted to enjoy it. I thought of
the movie Lawrence of Arabia, in which T.E. Lawrence says, 'The
trick is not minding that it hurts.' I told myself that the mild
ache was only the sensation of evaporating fat. That interpretation
has some basis in physics. When you lose weight, most of your fat
is converted to the gases carbon dioxide and water vapor, and so
you get rid of fat by breathing it out of your body.
Physics works, and I lost weight. By August, I was down to 175
pounds, a 30-pound drop. My belt went from 42 inches to 36 inches.
My Zen-like approach to hunger also worked; I found myself
declining offers of chocolate cake because I didn't want to lose
the sensation of evaporation. I didn't change my level of activity,
and managed to maintain my diet while taking trips to Cuba and
Alaska -- and during a week-long backpacking excursion in the
Sierra Nevada.
A key innovation: I kept up the social aspects of lunch, without
eating. I watched others gobbling cheeseburgers, while I sipped
diet cola. It really wasn't that hard to do. And the mild afternoon
discomfort was compensated by several positive developments. Dinner
became truly wonderful. I hadn't had pre-dinner hunger for decades.
A sharp appetite turns a meal into a feast. No more cheese
'appetizers' for me.
Moreover -- and this may sound silly coming from a physicist -- I
was surprised that I began to feel lighter. I no longer walk down
streets -- I float. Distant stores seem closer. And my knees have
responded to the lighter load. Their aching, which I had mistakenly
attributed to aging, went away.
Food is instant gratification. And fast-food chains and gourmet
restaurants serve tasty food at remarkably low cost. It is a
situation unprecedented in history and unanticipated by our genes.
No wonder we are overweight.
Anybody can lose weight. Energy is conserved. Just stop scratching
that itch. Of course, you'll have to sacrifice instant
gratification. Is it worth it? You decide. Food is delicious and
cheap. You might reasonably choose to take advantage of this unique
historical circumstance, and decide to be fat.
It's been seven months since I started my diet, and two months
since I left it. I've begun eating a light lunch, and having an
occasional small snack. I'm still at 175. But I never want to lose
the delicious edge of hunger before dinner, or the floating
sensation when I walk. Moving takes less energy now, so I have more
energy. I no longer feel like a spherical physicist. And for losing
weight, dieting sure beats cleaning animal stalls.
—Note: this answer is based on an essay I wrote in 2003 for MIT’s
“Technology Review.” I have gained back a bit of weight since then,
mostly because I now eat lunch about half the time. I currently
weigh 185 lb. That’s still 20 lb. lighter than when I started the
physics diet, and pretty good for 14 years later.
