Lighten Your Heaviest Gear: You!

It will take me a while to find the relevant links, as this is knowledge that I have synthesised over several decades of study in this area. However, I will admit it is more complicated than my simple statement above, eg men's appetite respond better (decrease) more after short term high intensity exercise, whereas women often experience an increase in hunger after the same intensity of exercise. There is also a lot of individual variation.

Here's a link to the swimming statement to get you started.

http://www.ncbi.nlm.nih.gov/pubmed/15902988?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=5

I'd be interested in research that shows that "exercise contributes little or nothing to weight loss." I would tend to agree that exercise, BY ITSELF, OFTEN contributes little or nothing to weight loss. I would agree that without a corresponding change in eating habits, including controlling your food intake at a conscious level, you can defeat your best intentions. But that's altogether different from your original, blanket statement!

And, of course, I'll always go back to one of my original points: it's not weight loss you should be after, it's fat loss. And those are two different things as well.

Of course execise is not over-rated. But some exercise does add muscle and weight. And exercise probably adds to our appetite.

Bottom line is that you need to burn more calories than you take in.

The other factor is metabolism. I am blessed with a metabolism that keeps my weight in check. I weigh close to what I was 40 years ago. I attribute some of this to diet and excercise, but mostly genetics.

http://eje-online.org/cgi/content/full/160/5/759

Objective: Weight loss with preferential effect on the visceral adipose tissue (VAT) depot could have important clinical benefits. In this study, we investigated the independent and combined effect of regular exercise and diet induced weight loss on body fat distribution.

Design: Randomized control design of i) exercise-only (EXO; 12 weeks of exercise without diet-restriction), ii) hypocaloric-diet (DIO; 8 weeks of very low energy diet (VLED 600 kcal/day) followed by 4-weeks weight maintenance diet) and iii) hypocaloric-diet and exercise (DEX; 8 weeks VLED 800 kcal/day+a 4-week weight maintenance diet combined with exercise throughout the 12 weeks).

Subjects: Seventy-nine obese males and females were included.

Measurements: Body fat distribution was quantified by magnetic resonance imaging (MRI)-technology.

Results: In the EXO group, the weight loss (3.5 kg) and the relative reduction in VAT (18%) was significantly lower compared with the weight losses in the DIO and DEX groups (12.3 kg; P<0.01) and to the reduction in VAT (30–37%; P<0.01). In all the three groups, the relative reduction of VAT was higher as compared with the reduction in fat mass (FM; combining all fat depots determined by MRI; P<0.01 for all comparisons). The changes in VAT were associated with changes in FM and related to the initial VAT/FM ratio (r2=0.72; P<0.01).

Conclusion: Exercise has no additional effects in reduction of the VAT depot, compared with the major effects of hypocaloric diet alone. In addition, the effects of exercise per se on VAT are relatively limited. The effects on the VAT depot are closely associated with changes in total FM.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806223/?tool=pubmed

There is debate over the independent effects of aerobic fitness and body fatness on mortality and disease risks.
PURPOSE
To determine whether a 25% energy deficit that produces equal change in body fatness leads to greater cardiometabolic benefits when aerobic exercise is included.
METHODS
Thirty-six overweight participants (16 males/20 females) 39±1 y; 82±2kg; BMI=27.8±0.3 Kg/m2, mean±SEM) were randomized to one of three groups (N=12 for each) for a 6-month intervention: control (CO: weight-maintenance diet), caloric restriction (CR: 25% reduction in energy intake) or caloric restriction plus aerobic exercise (CR+EX: 12.5% reduction in energy intake plus 12.5% increase in exercise energy expenditure). Food was provided during weeks 1–12 and 22–24. Changes in fat mass, visceral fat, VO2peak (graded treadmill test), muscular strength (isokinetic knee extension/flexion), blood lipids, blood pressure and insulin sensitivity/secretion were compared.
RESULTS
As expected, VO2peak was significantly improved after 6 months of intervention in CR+EX only (22±5% vs. 7±5% in CR and −5±3% in CO) whereas isokinetic muscular strength did not change. There was no difference in the losses of weight, fat mass or visceral fat and changes in systolic BP between the intervention groups. However, only CR+EX had a significant decrease in diastolic BP (−5±3% vs. −2±2% in CR and −1±2% in CO), in LDL-cholesterol (−13±4% vs. −6±3% in CR and 2±4% in CO), and a significant increase in insulin sensitivity (66±22% vs. 40±20% in CR and 1±11% in CO).

http://jcem.endojournals.org/cgi/content/full/92/3/865

Context: There is debate over the independent and combined effects of dieting and increased physical activity on improving metabolic risk factors (body composition and fat distribution).

Objective: The objective of the study was to conduct a randomized, controlled trial (CALERIE) to test the effect of a 25% energy deficit by diet alone or diet plus exercise for 6 months on body composition and fat distribution.

Design: This was a randomized, controlled trial.

Setting: The study was conducted at an institutional research center.

Participants: Thirty-five of 36 overweight but otherwise healthy participants (16 males, 19 females) completed the study.

Intervention: Participants were randomized to either control (healthy weight maintenance diet, n = 11), caloric restriction (CR; 25% reduction in energy intake, n = 12), or caloric restriction plus exercise (CR+EX; 12.5% reduction in energy intake + 12.5% increase in exercise energy expenditure, n = 12) for 6 months.

Main Outcome Measures: Changes in body composition by dual-energy x-ray absorptiometry and changes in abdominal fat distribution by multislice computed tomography were measured.

Results: The calculated energy deficit across the intervention was not different between CR and CR+EX. Participants lost approximately 10% of body weight (CR: – 8.3 ± 0.8, CR+EX: – 8.1 ± 0.8 kg, P = 1.00), approximately 24% of fat mass (CR: – 5.8 ± 0.6, CR+EX: – 6.4 ± 0.6 kg, P = 0.99), and 27% of abdominal visceral fat (CR: 0.9 ± 0.2, CR+EX: 0.8 ± 0.2 kg, P = 1.00). Both whole-body and abdominal fat distribution were not altered by the intervention.

Not withstanding all of the above, as I said earlier, exercise has some very important effects on overall health aside from weight loss, and is essential to maintain any weight lost through caloric restriction, it just isn't that big of a contributor to actual weight loss in already obese individuals. My comment to it being "over-rated" was in response to the topic of this thread, which is "lightening your heaviest load" rather than any independent health benefits.

"nm..no sense in commenting on bizarre statements."

+1

""nm..no sense in commenting on bizarre statements.""

???? No sense on commenting on scientific information intended to inform? I am not negating the benefits of exercise at all, merely pointing out that it's contribution to weight loss, and indeed fat loss, is minimal compared to calorie restriction for most overweight/obese folks.

"nm..no sense in commenting on bizarre statements."
+2
I understand the feeling. It seems like common sense right?
When you exercise, you burn calories. When you exercise consistently, your body expects to burn calories and increases your metabolism accordingly. Not rocket science. Not negating the benefits of a healthy diet, but exercise alone CAN make you lost weight.

Lynn,

That info left me with a number of questions and concerns.

For example, the first study used a hypocaloric diet that sounded to me as if it was technically starvation level. That is known to reduce metabolism. Am I missing something, or was that somehow accounted for?

In the second and third studies, the exercise group dieted less than the pure diet group. I note that the third study says that the calculated energy deficit was the same. They found (no surprise) that the weight loss was the same in both cases — why not, if the energy deficit was the same? The also found non-weight loss benefits for exercising. I'd say exercising was doing just fine.

I presume that if they did what more real-world people will try to do — add exercise without increasing food intake — that the would have seen extra weight loss in the exercise group as well as the extra exercise benefits.

This research seems to support what I think most of us believed going in:
* what matters to weight loss is calorie deficit, regardless of how you achieve it.
* exercise is one way to achieve a calorie deficit, and has other benefits besides.

I note that the cited research did not deal with the question of using exercise that produced additional muscle mass, and the longer term effects of the consequent increased metabolism. That is one way that exercise may be better than just dieting, but was outside the scope of the research cited.

The term "exercise" was not well enough defined in some of the studies. How vigorous was the exercise, and what kind was it? Was the exercise enough to gain any muscle mass? There is a difference between the calories expended in the exercise session itself and ongoing increased metabolism due to increasing muscle mass.

For the cases where there was exercise and no diet control, how did the participants respond? Did they eat more? Obviously, to the extent they ate enough to compensate for their exercise, there would be little or no weight loss.

— Bob

You know, it sometimes seems to me that there is a huge un-orchestrated campaign to hide the fact that the major cause of obesity is simply eating too much. People just do not want to admit that if they ate less (and better food) they would weigh less.

So we see all sorts of studies into genetic and environmental effects as a sort of sop to the desire to claim to be healthy while relentlessly over-indulging. I'm sure there are 'contributing factors', but they only contribute to the basic problem.

Sure, exercise is good for you, in all sorts of ways. (I'm sure Lynn can fill in the details with published refereed research.) But research has repeatedly shown if you pig out you …

Proof? Compare body weights between the indulgent West and the more caloric-restricted Third World.

Cheers
(Ducks for cover!)

Anecdotaly, I have experienced this myself. I worked a very hard physical job and after, worked out at home and regularly took walks and hikes. I was as active as you could expect a reasonable person to be.
and I was strong ( I used to snatch 62 lb kettelbells ) muscular, had great endurance and yet was battling a growing "beer" belly. Any casual look at power-lifters and the like will show you the same.
I now have a six pack -what I changed is what I eat, it was overwhelmingly the diet that changed things.
I don't believe in nor practice calorie restriction either*- but thats a whole other thread.
For the obese they simply cant not physically burn off the calories through exercise-they are not fit enough. And exercise does increase your appetite its insane to suggest otherwise. So how does that help them? yes, they should start to become active but active for the obese is a short walk-that short walk takes as much out of them as a 5 mile run takes out of a really fit person. Diet is number one.
another riddle:
are you fit because your more active or are you more active because your fit?
edit to make this clear
* As a practical matter I don't believe its helpful but of coarse calories do have an effect I just don't see it as the biggest practical concern.

Roger,

> But research has repeatedly shown if you pig out you …

Of course you are right. I do not know anyone who claims that anything other than a calorie deficit will lose weight. Whatever other exercise you do, you need to do push-aways (from the dining table). Consider a sumo wrestler — I presume they are strong, but …

> Proof? Compare body weights between the indulgent West and the more caloric-restricted Third World.

Perhaps not that simple? It seems to me that the third world also tends to be less sedentary — i.e. gets more exercise, even if not recreationally :) It does not take much exercise to have a notably higher daily caloric expenditure.

As far as I know, the claims that exercise is an important part of a weight loss plan hinge on the following:

* Exercise will minimize the muscle lost along with the fat (or with enough of the right kind of exercise, even gain muscle). As a result, when you are done losing a given amount of weight your fat percentage will be lower and you will have more muscle than otherwise. That is good for you and makes it less likely to regain the weight (the weight-loss yo-yo).

* To the extent you end up with more muscle, you end up with a higher metabolism, which helps keep the weight off and makes you more energetic, also good for you.

* The exercise itself does contribute to the calorie deficit, and so accelerates the weight loss (as compared to the same diet without exercising). This is probably less important than the other points.

* The exercise has non-weight loss benefits, such as aerobic and helping preserve bone strength.

To the extent these are true, they sure sound like benefits to me. Which of these is Lynn, or anyone else, saying is illusory?

— Bob

First, I am still talking about weight loss, not about all the other great benefits of exercising.

"That info left me with a number of questions and concerns."

Good. An enquiring mind is better than just disregarding info because you do not agree with it based on "common sense".

"the first study used a hypocaloric diet that sounded to me as if it was technically starvation level. That is known to reduce metabolism. Am I missing something, or was that somehow accounted for?"

Yes, they measured changes in REE. From the methods section: "In these two (VLCD) groups, we intended the subjects to obtain similar weight losses in order to see the possible specific – weight independent – effect of exercise. Thus, the subjects in the DEX group were allowed to consume 150–200 kcal more per day as compared with the DIO group, reflecting the estimated extra energy expenditure of 1500 kcal/week during exercise activity."

"In the second and third studies, the exercise group dieted less than the pure diet group. I note that the third study says that the calculated energy deficit was the same. They found (no surprise) that the weight loss was the same in both cases — why not, if the energy deficit was the same? "

Seems you are arguing both sides of the coin here. You are not happy with the first study because both groups were on a similar VLCD intake, yet you are not happy with other two studies for the opposite reason, ie because the exercise group ate more (which was my original point).

"The also found non-weight loss benefits for exercising."

No one is denying this!!! Again, the topic of this thread is "weight loss", not "health benefits.

"I presume that if they did what more real-world people will try to do — add exercise without increasing food intake — that the would have seen extra weight loss in the exercise group as well as the extra exercise benefits."

This is not the real world I live in. As a retired PT and ex-bodybuilder, I have been at the same gym for almost 30 years. Over that time, all the other long time members (as well as myself) have gained appreciable weight, even with 5 or more session every week. In the "real world", unless you consciously monitor and restrict you energy intake (that is what "add exercise without increasing food intake " is), exercise alone doesn't cut it.

"* what matters to weight loss is calorie deficit, regardless of how you achieve it.
* exercise is one way to achieve a calorie deficit, and has other benefits besides."

Undeniably. But again, I stress that that exercise must be accompanied by intentional energy restriction. You can't just exercise and trust your appetite will not compensate.

"I note that the cited research did not deal with the question of using exercise that produced additional muscle mass, and the longer term effects of the consequent increased metabolism. That is one way that exercise may be better than just dieting, but was outside the scope of the research cited."

I can give you more research in this area, but again, strength conditioning by itself it is underwhelming in it's ability to promote weight loss. I could list zillions of references and put everyone to sleep, or you can go do your own research (and I don't mean Google). As this is my area of expertise, I come across this kind of info all the time, but it would take me too long to assemble the entire body of research in this forum, and is not really important. You will believe what you want.

"There is a difference between the calories expended in the exercise session itself and ongoing increased metabolism due to increasing muscle mass."

Yes, but it is minimal, and long term appetite still compensates for this extra energy expenditure.

"The term "exercise" was not well enough defined in some of the studies. How vigorous was the exercise, and what kind was it? "

All the cited studies provided detailed info on the exercise type, intensity, duration and estimated calorie expenditure of the exercise. All three of the above were based on aerobic exercises. They also measured fat-free mass at the start and end of the studies.

"For the cases where there was exercise and no diet control, how did the participants respond? Did they eat more?"

Again, from the methods section:
"The subjects in the EXO group were advised to maintain an isocaloric diet for the duration of the intervention. Thus, the possible change in the body composition would be due to the differences in the energy expenditure during the exercise activity. Their daily energy expenditure during the intervention was determined by estimating the resting energy expenditure multiplied by a factor of 2.5." I would assume they ate more, otherwise they would have lost more weight! Again we come back to my initial statement, that exercise alone (without intentional energy restriction), just leads to a comparable increase in appetite.

Im loath to get into this but:
"Proof? Compare body weights between the indulgent West and the more caloric-restricted Third World."

the more wealth you have the more refined sugars and grains you eat as a society. Insulin tells the body to store fat and spare stored fat reserves. Therefore if you eat these foods your setting yourself up for failure regardless of the amount of calories you eat.(within practical limits)
Hormones rule your body not the simple thermodynamics of combustion engines and different foods effect hormones differently.

Brian,

> I used to snatch 62 lb kettelbells

(For those who do not know, that is very good — 53# kettlebells are a fairly standard weight and all a lot of people do — once they work up to them.)

I do not want to get too far off topic, but would like to ask a quick question or two.

I have gotten curious about kettlebells. How did you like them? Did you use them exclusively, or integrated with the rest of a weight workout? How well did they work for you? I gather you have stopped using them — if I am not being too intrusive, why?

Thanks,
Bob

Robert ,
I love kettlebells! they are great for so many reasons, the biggest one is that you get a combination of aerobic and strength training all in one. I also don't have that "off" feeling in the joints and shoulders like with dumbbells that leads to injuries. But bottom line ketlebells just kill you. Once you try them there is no mistake that these give you a serious workout.
and yes Ive cooled off on any weight training for now and have been concentrating on bodyweight exorcises as well training hard in martial arts a few times a week.

Brian,

> I now have a six pack -what I changed is what I eat, it was overwhelmingly the diet that changed things.

What changed? Caloric intake, or was it what kind of food you ate? (Your later posting suggests you may have changed to a low carbohydrate diet.)

Lynn, Brian,

It sounds to me as if the exercise-does-not-lose-weight point is that exercise increases appetite, and if you eat without thinking you will eat enough calories to overcome any exercise-related calorie expenditure. That is easy to agree with — look at some of the web sites that note the calorie loss for an hour of aerobic exercise, and then show how people obliterate their good work by eating a muffin or a Starbucks right afterward.

Clearly, you must be careful to maintain or reduce your caloric intake (including allowing for calories in your electrolyte drinks and recovery shake, if you have those things).

While I agree, I am puzzled by some things from my own experience — times when I exercised, ate what I felt like, and still lost weight — back around college age, if that matters. Seems like they contradict the above. For example, I lost weight and got stronger at both of the following:

* I worked trail crew one summer. Got pretty strong — did such things as 50 mile hike (walk, not run) and broke my Kelty pack frame carrying about 140# up over a small mountain. I lost about 5-10# that summer.

* At a geology field camp one summer, I was worried about afterward so I added a handful of pebbles to my pack each day. Every day I was active in the field, and every day I had a heavier pack (by the added pebbles for that day). By the end of a month of that, I was definitely strong and had lost about 5-10#.

— Bob

It depends.

Maybe you want to gain weight. Maybe you want to make a ton of money by doing so.

NFL Colts over 300 lb…

78 Pollak, Mike G ACT 6'3" 301
67 Ugoh, Tony T ACT 6'5" 301
69 Gill, John DT ACT 6'3" 302
95 Moala, Fili DT ACT 6'4" 303
75 Toudouze OT ACT 6'6" 303
74 Johnson T ACT 6'4" 305
66 DeVan, Kyle G ACT 6'2" 306
99 Johnson DT ACT 6'3" 310
90 Muir, Daniel DT ACT 6'2" 312
71 Diem, Ryan T ACT 6'6" 320

I found the following interesting….

http://www.forbes.com/2008/06/20/australian-obesity-survey-markets-equity-cx_jc_0620markets06.html

HONG KONG –
The astonishing speed with which Australians are adding weight has enabled the country to clam an unsavory title: fattest country among the world's major economies.

Quietly but surely, more than a quarter of the Australian adult population, 26% of its 15.1 million, has become obese, compared with 25% in the United States, according to a comprehensive survey, titled "Australia’s Future Fat Bomb," released Friday by the Melbourne-based Baker IDI Heart and Diabetes Institute. That would put Australia, a nation associated in the popular imagination with sports and outdoor activity, ahead of America as the world's fattest major country.

and…

http://www.forbes.com/2007/02/07/worlds-fattest-countries-forbeslife-cx_ls_0208worldfat_2.html

No matter how you tip the scales, Americans are getter wider every year. What's worse is that many nations are following suit.

In a list of the countries with the greatest percentage of overweight people, Nauru tops a list of countries with the greatest percentage of overweight people, with an alarming 94.5% of its adult population (ages 15+) classified as such, based on the most recent estimates by the World Health Organization (WHO). The Federated States of Micronesia, Cook Islands, Niue and Tonga round out the top five, all with a portly population of over 90%.

The U.S. weighs in at No. 9, with 74.1% of those over 15 years old considered overweight. But given that its population is nearly 20,000 times that of Nauru, clearly the U.S.’s size belies it rank.

"What changed? Caloric intake, or was it what kind of food you ate? (Your later posting suggests you may have changed to a low carbohydrate diet.)"

i changed what I eat, I am a fan/follower of Taubes.

" look at some of the web sites that note the calorie loss for an hour of aerobic exercise, and then show how people obliterate their good work by eating a muffin or a Starbucks right afterward."

LOL. That is exactly what happens, like Roger said ;)

"times when I exercised, ate what I felt like, and still lost weight — back around college age, if that matters."

Ah yes, the army effect. Take a young male in his testosterone prime and throw heaps of exercise at him, and he will definitely get stronger and lose weight. I too used to eat whatever I wanted and never gained weight. Two things that are worth considering are that it is much easier for someone who is young and not yet fat to exercise off a few spare kilos, then it is for someone who is older or more overweight. Exercise DOES have a positive impact on weight loss in children and adolescents. It is also harder for females to lose fat via exercise (as mentioned earlier, this is partly due to an increase in hunger than men are less prone to). The other thing to remember is that your body adapts and gets used to anything it does routinely. A new exercise regime may result in enhanced fat loss initially, but over the long term your body gets more efficient at doing that activity. This leaves you with two alternatives: Either increase the frequency and duration of your exercise, or change it regularly. Using the army analogy, boot camp often results in weight loss, but if you stayed in boot camp the rest of your life, the benefits would gradually diminish. It is the shock to the system that partly moderates increases in appetite and revs up energy expenditure.

And yes, Brian has adopted a paloelithic diet that suits him well. I certainly can't burn off the junk carbs that I used to eat as an overly active youth! I too have cut back a lot on these kinds of foods.

A meta-analysis of the effects of exercise and/or dietary restriction on resting metabolic rate.

A meta-analysis was used to examine the independent and interactive effects of dietary restriction, endurance exercise training and gender on resting metabolic rate (RMR). Sixty different group means (covering approximately 650 subjects) were identified from the scientific literature and subjected to meta-analysis techniques. Collectively (i.e., all groups combined), body weight loss was greater (P < 0.05) for men (approximately 18 kg) than for women (approximately 12 kg). There were no statistically significant exercise training or gender effects on RMR during weight loss. Collectively (i.e., all groups combined), dietary restriction resulted in a -0.59 kJ.min-1 (approximately -12%) decrease in RMR (P < 0.05). When normalized to body weight, RMR was reduced by less than 2% (P < 0.05). These data suggest that exercise training does not differentially affect RMR during diet-induced weight loss.

For preserving muscle mass, but not resting metabolic rate:

Effects of strength or aerobic training on body composition, resting metabolic rate, and peak oxygen consumption in obese dieting subjects.

Given that resting metabolic rate (RMR) is related largely to the amount of fat-free mass (FFM), the hypothesis was that strength training, which stimulates muscle hypertrophy, would help preserve both FFM and RMR during dieting. In a randomized controlled intervention trial, moderately obese subjects (aged 19-48 y) were assigned to one of three groups: diet plus strength training, diet plus aerobic training, or diet only. Sixty-five subjects (25 men and 40 women) completed the study. They received a formula diet with an energy content of 70% of RMR or 5150 +/- 1070 kJ/d (x +/- SD) during the 8-wk intervention. They were seen weekly for individual nutritional counseling. Subjects in the two exercise groups, designed to be isoenergetic, trained three times per week under supervision. Those in the strength-training group performed progressive weight-resistance exercises for the upper and lower body. Those in the aerobic group performed alternate leg and arm cycling. After 8 wk, the mean amount of weight lost, 9.0 kg, did not differ significantly among groups. The strength-training group, however, lost significantly less FFM (P < 0.05) than the aerobic and diet-only groups. The strength-training group also showed significant increases (P < 0.05) in anthropometrically measured flexed arm muscle mass and grip strength. Mean RMR declined significantly, without differing among groups. Peak oxygen consumption increased the most for the aerobic group (P = 0.03). In conclusion, strength training significantly reduced the loss of FFM during dieting but did not prevent the decline in RMR.

And in men only, not women :(

Purpose: The purpose of this study was to compare age and gender effects of strength training (ST) on resting metabolic rate (RMR), energy expenditure of physical activity (EEPA), and body composition.

Methods: RMR and EEPA were measured before and after 24 wk of ST in 10 young men (20-30 yr), 9 young women (20-30 yr), 11 older men (65-75 yr), and 10 older women (65-75 yr).

Results: When all subjects were pooled together, absolute RMR significantly increased by 7% (P < 0.001). Furthermore, ST increased absolute RMR by 7% in both young (6302 ± 1458 vs 6719 ± 1617 kJ·d-1, P < 0.01) and older subjects, with no significant interaction between the two age groups. In contrast, there was a significant gender × time interaction (P < 0.05) for absolute RMR with men increasing RMR by 9%, whereas women showed no significant increase. When RMR was adjusted for fat-free mass (FFM) using ANCOVA, with all subjects pooled together, there was still a significant increase in RMR with ST. Additionally, there was still a gender effect (P < 0.05) and no significant age effect (P = NS), with only the men still showing a significant elevation in RMR.

Brian wrote:

> the more wealth you have the more refined sugars and grains you eat as a
> society. Insulin tells the body to store fat and spare stored fat reserves.
Indeed.

So the solution has to include a change in your diet away from what the major food companies want to sell you. In practice this means eating less 'prepared' and 'take-away' foods, as they are usually the biggest offenders.

Yes, like Lynn I used to be able to eat anything and hold a fixed weight. (Those were the days …) Sadly, not today. So these days Sue and I eat very well, but the foods we eat are very much more along the lines of "Grandma's diet", and the quantities are way smaller than for most people. Sue does all her own cooking, and we would open maybe one tin every 2 – 3 weeks. Sue makes her own bread using wholemeal flour. Desert – fresh (chopped up at home) fruit salad and home-made yoghurt.

Curiously, neither Sue nor I feel in any way deprived or restricted. Sue's comment just now was that she couldn't eat any more anyhow, and I would say the same. That probably means our stomachs have shrunk a bit – ie below the average beer belly size. Or maybe they have just stayed small?

But despite all this both of us are perfectly capable of going for a 2 month walking tour in Europe or a week-long ski-touring trip. Our return weights are usually close to our departure weights – down maybe 4 -6 lbs after 2 months for instance.

Face it: the fat in a body can only come from the food eaten.

Cheers

Wow, Lynn, thanks for the research! That is a huge surprise to me, and goes against my experience. But who am I to put personal anecdote against actual studies?

I suspect that there's something like this going on: since most of my exercise is in the form of commuting, and since I don't bike much when it's really cold, and since the cold season coincides with all those tasty solstice-oriented changes in diet, there are some correlations that I wasn't fully appreciating.

It makes perfect sense, but do you have at your fingertips a more concrete explanation of why we eat more than we burn in the winter? Does colder air or less light make people hungrier? Is this standard? If so, do over-air-conditioned offices make us fat?

Glad to know that exercise is still healthy anyway ;)

I have Type 1 Diabetes. This discussion is especially relevant for me because of the way that an insulin-dependent diabetic has to think about and process the insulin, exercise, and food. Before I became a diabetic I never gained weight. And in the first year of my getting the disease I was able to completely control the blood sugars by exercise and diet alone. But as my insulin-making abilities gradually ran dry more and more I became dependent on insulin to keep my blood sugar levels down.

You quickly find out that insulin is the agent that causes people to gain weight. Since I started using insulin I have gained weight and even with lots of exercise I cannot lose it. Two years ago I trained in the Crossfit program for 9 months, gaining muscle mass and able to do 50+ full, Crossfit style pull ups plus deadlift 70 kg. Because I didn't change my diet much I gained both the muscle weight plus the fat that didn't go away. I'm sure that if I had changed my eating habits and continued the program long enough for my body to incorporate the changes I would have started to lose weight, but certainly the diet was key to making that change.

Then, last year, when I went through a great personal crisis and only ate the most basic foods I needed, but did hardly any dedicated exercise at all, I lost 7 kg in three months. I was back down to my college level weight. My intake of insulin decreased dramatically, too, and for the first time in 7 years all the points on my physical checklist turned up perfect. So eating less food made a huge difference in how my body handled its weight and homeostatic balance.

Most overweight people are overweight not so much because of lack of exericise, but from a hormornal imbalance. Put very simplistically, insulin is a hormone that acts upon carbohydrates to help regulate blood sugar. It's what helps to convert carbohydrates into fat, for storage in lean times. Evolution-wise people who tend to get fat easily are actually genetically predisposed to surviving times of famine. That is why groups of people around the world, like Native Americans, who until recently often faced famine, have such high rates of obesity; the super-abundance of foods they now eat overbalance the older boom and bust diets they ate and their bodies overcompensate with excessive levels of insulin. Right now, with the high level of insulin that I am taking, I have essentially become an obese-type person whose insulin levels make me fat.

In this way the type of food you eat is also just as important as how much you eat. Too many carbohydrates and the insulin levels increase, thereby causing you to gain weight. While I don't agree that extremely low carbohydrate diets are healthy in the long-term, I do think that restricting carbohydrates to a lesser role in the diet is very important. Americans eat extremely high amounts of carbohydrates… far higher than the body can handle… and far, far too many calories. That is why obesity is so prevalent in these countries. Japanese are rarely overweight because they eat less. An average restaurant meal is half the size of an American one. If you look at old photographs of Americans 150 years ago you will see that they are far less obese than today… in part because they were much more physically active and because they ate less.

Exercise does play a very important role. It helps to condition your body to process nutrients better, improves circulation to help distribute those nutrients, helps to regulate hormones, brings in a better ratio of oxygen and carbon dioxide for the blood, reduces the stress that contributes to the need for hunger, to name just a few. You can say that the feet are the body's "second heart" and that by walking the circulation and nutrients are better controlled.

I stopped Crossfit because it was too intense for my body. The stress alone was causing constant swelling and problems with my stomach. It did however, eliminate the excruciating thigh cramps I had had and made my heart strong. I settled instead for something more easygoing on my stress levels : long walks, some jogging, stretching, and Pilates for strength. It's taking a long time, but the benfits are slowly beginning to manifest themselves.

It's the diet I really have to work on, though. less carbohydrates to react with my insulin. More vegetables. A good balance of protein and fat. I'm just not sure of the right combination, though. The best diet I ever followed was the one put out by the Japanese medical establishment, which recommends eating "thirty-five different kinds of vegetables [in small amounts] a day.". In the traditional Japanese diet this is no problem; it's following this with modern foods and limited choices in supermarkets that makes this very hard to follow. I gave up because trying to find the right foods during lunchtime in downtown Tokyo was next to impossible. Everything has too many carbohydrates and calories (here in Japan the recommended daily caloric allowance for someone of my age and weight here is 1900 kcal, considerably lower than the American standard).

Just some observations. I have so much to learn still!

> An average restaurant meal is half the size of an American one.

One cannot help noticing that restaurant portions are HUGE in the USA. I have long wondered whether that is because of customer demand, or economics.

I am suspicious that they would need to charge almost as much if the portions were half the size, and then the food would look like a lot less of a value. I am suspicious that most of their cost is labor and overhead, not the actual food itself.

— Bob