Sunday, October 22, 2006

"Body" -> Diet And Losing Weight

If you want to lose weight and not feel as much hunger, you need to eat around 150-200 grams of protein per day. This is a lot, and if you have problems with your kidneys, it will NOT be healthy. However, if you don't want the short version, then you'll want to think through this for yourself.

Okay, hang onto your hats, we are going to dive into some research. The first thing that you want to do is go here, and have this paper handy.

David S Weigle et al, did a very interesting experiment.

To describe what happened:

1. They fed the 19 individuals 15% protein for two weeks. (This period is call from zero to CRC1 on the graph below.) The folks didn't gain any weight. They were eating around 2300 calories.

2. They fed them 30% protein for the next two weeks at "maintenance calories." (This period is CRC1 to CRC2 on the graph below. Maintenance calories mean the subjects were fed by the doctors around 2300 calories, because they didn't want them to lose weight.)

3. They then asked them to eat 30% protein ad libitum (which just means whenever they wanted), which caused them to drop under maintenance caloric intakes, thereby losing weight. In essense, if you eat a lot of protein, you don't feel as hungry.

So let's look at the first graph:

You can see the periods on the graph. For the first two periods, the researchers fed people enough calories to keep them pretty much at the same weight. If you draw a line through the little circles, you will see they were eating around 2300 calories per day to keep their weight.

Now, after the CRC2 time, they sent the people home but told them to eat 30% of the calories from protein. What happened is that people stopped eating as much! If you look at the first chart, you can see their weight as a line. During the first two sections, the line is pretty flat. However, as soon as they went to eat 30% protein on their own, the line starts going down very quickly.

The question is "why did they stop eating so much?"

The next graph answers the question.

This graph shows the same time period, but the subjects were asked "are you hungry or are you full?" (This is a bit oversimplified, but good enough for us.) The little circles are "hunger" so when the little circles go down, you are less hungry. Now, one of the things that is important to note not being hungry is NOT the same as being full.

In the first phase, the little hunger circles were around 25-30.

In the second phase, the little hunger circles dropped to 10! They were never hunger. They even felt a bit more full.

In the final phase, you can see that people naturally went back to 25-30 on the hunger circles. Interestingly, this actually made them eat less than what they need to eat to maintain their weight, and they started to drop weight.

On a high protein diet, the individuals did not "feel stuffed." Yes, the little triangles went up, but not as much as the little circles went down. Therefore, the didn't have hungry, but they didn't feel full as much as they felt lack of hunger.

In the third phase, the individuals were sent home and told "eat a lot of protein."

Since they weren't as hungry, they simply stopped eating as much. This in turn caused them to lose weight. Where they were eating around 2300-2400 calories, they dropped to 1900 calories.

According to Weigle, "Only one long-term, controlled ad libitum feeding study by Astrup et al (10, 30) has been designed specifically to investigate the effect of increased dietary protein content on spontaneous energy intake and body composition. In this study, both the reduction in caloric intake and magnitude of weight loss at 6 mo in the subjects who consumed a 25% protein diet were significantly greater than the values observed in subjects who consumed a 12% protein diet (10)."

This is not to say that some research hasn't been done on a short basis. For example, Westerterp-Plantenga, who was an author on the following, experiments with the high protein interactions with a short stint in a respiration chamber.

Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber.

* Lejeune MP,
* Westerterp KR,
* Adam TC,
* Luscombe-Marsh ND,
* Westerterp-Plantenga MS.

Department of Human Biology, Maastricht University, Maastricht, The Netherlands.

BACKGROUND: The mechanism of protein-induced satiety remains unclear. OBJECTIVE: The objective was to investigate 24-h satiety and related hormones and energy and substrate metabolism during a high-protein (HP) diet in a respiration chamber. DESIGN: Twelve healthy women aged 18-40 y were fed in energy balance an adequate-protein (AP: 10%, 60%, and 30% of energy from protein, carbohydrate, and fat, respectively) or an HP (30%, 40%, and 30% of energy from protein, carbohydrate, and fat, respectively) diet in a randomized crossover design. Substrate oxidation, 24-h energy expenditure (EE), appetite profile, and ghrelin and glucagon-like peptide 1 (GLP-1) concentrations were measured. RESULTS: Sleeping metabolic rate (6.40 +/- 0.47 compared with 6.12 +/- 0.40 MJ/d; P < p =" 0.05)." r2 =" 0.49,">CONCLUSION: An HP diet, compared with an AP diet, fed at energy balance for 4 d increased 24-h satiety, thermogenesis, sleeping metabolic rate, protein balance, and fat oxidation. Satiety was related to protein intake, and incidentally to ghrelin and GLP-1 concentrations, only during the HP diet.

PMID: 16400055 [PubMed - indexed for MEDLINE]

If you want to assume a man needs around 2400 calories, a protein consumption of 30% would be approximately 180g or a littel over 1g per lb, which is a lot of protein. Interestingly, bodybuilding athletes will often push closer to 2g/lb. In this case, you'd be at 360g of protein a day. This is roughly 400% more than the recommended protein levels. And, as I stated before, if you have kidney problems, this will be bad on them. However, a lot of bodybuilder have done this for extended periods, and we haven't heard of them dying all over the place. So high levels of protein can be sustained.

Finally, there may some speculation that an extremely high protein diet can be hard on the lower colon and may set up an environment that would foster colon cancer. It would appear that the use of fiber could limit this problem, especially something called resistant starch, which comes from beans. In generally, eat lots and lot of fiber.

Fiber is a big subject, and I'll try and get to it in a later post.

However, high levels of protein in the diet seem to be the best way of dumping the appetite. While the research is a bit spotty, it is promising.

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