Tag Archives: satiety

RD Turn-About: Fat Not So Bad

The American Dietetic Association is a low fat bastion, with member dietitians rarely advising patients to embrace a low-carb lifestyle. Doctors routinely refer their patients to Registered Dietitians for guidance, and their advice is normally horrendous. So it was with great interest that I read the news item regarding a presentation at the American Dietetic Association’s (ADA) Food and Nutrition Conference and Expo this month (November, 2010). From a news story in Food Navigator USA:

During a symposium called “The Great Fat Debate: Is There Validity In the Age-Old Dietary Guidance?” at the American Dietetic Association’s (ADA) Food and Nutrition Conference and Expo, four leading experts presented evidence suggesting that low fat diets may be less healthy than those containing at least a moderate amount of fat. In particular, all four agreed that replacing saturated fat with carbohydrates – as has been widely recommended in the United States – is likely to raise the risk of cardiovascular disease.

Emphasis mine. Just thought I’d bold that statement in case any deaf Dietitians were in attendance.

It is not that this is “new news”. The evidence has been mounting, and Low Carb Age has been documenting the end of the low fat diet craze for over a year now. But to have the ADA admit it is a very big deal indeed.

Just to recap some stories in the past year:

Dietary intakes of saturated fats are not linked to cardiovascular disease, so says a meta-analysis of 21 studies from across the world.

Data from almost 350,000 subjects obtained from 21 studies indicated that dietary intakes of saturated fat are not associated with increases in the risk of either coronary heart disease (CHD) or cardiovascular disease (CVD), US researchers report in the American Journal of Clinical Nutrition.

“Our meta-analysis showed that there is insufficient evidence from prospective epidemiologic studies to conclude that dietary saturated fat is associated with an increased risk of CHD, stroke, or CVD,” wrote the researchers, led by Dr Ronald Krauss from the Children’s Hospital Oakland Research Institute in California.

Japanese researchers noted an increase in mortality – that means death, folks – from strokes in those that adopted a low fat diet:

Very low intakes of saturated fats may be just as bad for you as very high intakes, and could lead to an increased risk of death from stroke – according to new Japanese research.

The study, published by the American Journal of Clinical Nutrition, suggests that a very low dietary intake of saturated fatty acids (SFA) is associated with an increased risk of stroke.

“SFA [saturated fatty acids – saturated fat] intake was inversely associated with mortality from stroke. This inverse association was similarly observed for intraparenchymal hemorrhage and ischemic stroke,” wrote the researchers.

Some of the stories show the conflicted nature of researchers facing unpleasant results. One study looked at low fat diets and concluded that it was the type of carbohydrates in the diet that were at fault:

People who cut saturated fats while increasing intake of refined carbohydrates like white bread and pasta have a higher risk of heart attack, according to a study published in the American Journal of Clinical Nutrition.

However, the Danish researchers found that reducing saturated fats while increasing intake of non-refined carbohydrates – such as wholegrain bread and vegetables – could improve heart health. A recent meta-analysis published in the same journal earlier this year called into doubt the widely held theory that high saturated fat intake is linked to high rates of heart disease – but the researchers behind that review said that other dietary elements of the 350,000 subjects involved could be more important.

. . .

They found a statistically significant correlation between replacing saturated fat calories with refined carbohydrates – those described as ‘high-GI’ and thought to cause a spike in blood sugar levels – and heart attack risk. For those subjects with the highest average dietary glycemic index, heart attack risk increased by 33 percent for every five percent increase in calorie intake from carbohydrates.

See the disconnect? I have emphasized the pertinent passage. They are still preaching the “whole grain breads” line while simultaneously saying that High Glycemic Index (GI) foods should be avoided. Yet whole grain bread often has a higher GI than plain old white bread (average of 62 vs. 59). You can see the official GI of different foods at http://www.glycemicindex.com/

Not that the gycemic index should really be a guide. For most Americans, cutting out refined carbs, including all breads, cookies, muffins and cakes, would go a long way toward curing the obesity problem in this country. Whole wheat and whole grain breads are still refined carbs, and spike blood sugar. Wheat may be implicated in numerous health issues due to allergies and sensitivities, sometimes hidden behind nebulous diagnoses of Chronic Fatigue Syndrome or PCOS.

Following a true low carb lifestyle, or adopting a paleo outlook to eating, would greatly enhance health while avoiding the hunger that plagues low fat dieters, and may clear up other health issues (as I found with eliminating GERD and insomnia).

Welcome to the club, dietitians!

Protein Intake: Special Cases

In our Protein Requirements article we looked at the minimum protein requirement as stated in Protein Power Lifeplan and how that compared to new research in the optimum daily protein values. But there are “special cases” that should be remembered: children, pregnant women, and those with other health issues. Remember, general rules of thumb cannot take the place of your family doctor.

Do the minimum protein values in low carb diets put women and children at risk?

The Perfect Health Diet blog commented on this recently. They are a bit different from other low carb, paleo advocates:

At PerfectHealthDiet.com we’re advocates of protein restriction. We recommend:

  • Avoiding all protein-containing plants, as plant proteins tend to be toxic
  • Striving to eat fatty, not lean, meats and fish, in order to keep protein intake down and fat intake up

Protein restriction helps protect against viral and bacterial infections by promoting autophagy, the process of intracellular protein scavenging, digestion, and recycling. During autophagy, bacteria and viruses, as well as junk human proteins and damaged organelles, are digested. Autophagy has been strongly linked to longevity and is protective against many diseases.

Our advocacy of low protein intake separates us from many other Paleo bloggers.

Of special concern is a protein-rich diet for infants and children; Perfect Health Diet points out that breast milk contains just 7% of its calories in protein, showing, in their view, that we evolved for lower protein intake as infants and children (they also cite other research showing problems with protein levels that would be appropriate for adults, but harmful for children). Pregnant women should also be careful of eating too much protein. Perfect Health Diet quotes Dr. Loren Cordain:

[Y]ou probably should increase your fat and carbohydrate consumption, and limit protein to about 20-25% of energy, as higher protein intakes than this may prove to be deleterious to mother and fetus for a variety of physiological reasons….

“Protein intakes above this [25% of total calories] threshold may affect pregnancy outcome through decreased mass at birth and increased perinatal morbidity and mortality.”

The physiological basis for this aversion stems from a reduced rate of urea synthesis during pregnancy that is evident in early gestation as well as increases in the stress hormone cortisol. Hence, pregnant women should include more carbohydrate and fat (i.e. fattier meats) in their diets and limit dietary protein to no more than 20-25% of their total caloric intake.

Perfect Health Diet recommends an even lower level of protein for pregnant women, to just 10% of their total calorie intake.

So how do you calculate the protein allowance as part of your total caloric intake? To simplify things, remember that each gram of protein has 4 calories. In this example, we’re using a woman who maintains her weight on a 2,000 calorie diet when not pregnant; most authorities say she should add an additional 300 calories during her baby’s gestation.

For a woman eating 2,300 calories a day, 20% of calories is 460, or 115 grams of protein (460 calories divided by 4 calories per gram equals 115 grams of protein). For the lower level, 10% of calories is 230 or about 58 grams of protein.

So how does the low carb Protein Power diet match up in this case?

First, remember the warnings about starting any new diet during pregnancy; they are in every low carb book I have seen. You simply should not begin any diet that isn’t approved by your physician during pregnancy. (Even if not pregnant, you should always talk to your physician prior to starting any diet, just to make sure you don’t have a condition that could be aggravated by the new diet.)

But again, we find that Protein Power is not a “high protein” diet plan. The recommendations on low carb diets for non-pregnant adults fall within the ranges cited above. For a 5′ 8″ non-pregnant woman weighing 140 pounds, the Protein Power Lifeplan chart recommends 27 grams of protein per meal, for a total of 81 grams. That represents 324 calories out of the daily total, or about 16% of the total for a 2,000 calorie intake.

I am not convinced Perfect Health Diet is right about reducing protein levels below these levels, especially for healthy adults. Satiety, the feeling of satisfaction or of being satisfied after eating, is said by many low carb advocates to come from getting a good proportion of your calories from fat. But research also shows that primates will increase their food intake to obtain more protein if only low protein foods are available. If hunger is a problem, you will cheat on your diet and consume more food than you should. Adequate protein intake may help provide a measure of satiety as well.

Obesity, Protein and Satiety

satiety, in dietary terms, is the lack of hunger or how much the diet satisfies you; it is tied closely to “lack of hunger”, a concept that is foreign to most frequent dieters.

Among those successful on low carb diets, dietary fat is often assigned the role as the macro-nutrient that provides the most satiety. But a core principle of the The Protein Power Lifeplan diet is the focus on getting at least the minimum amount of protein required to maintain muscle mass (generally, one half gram of dietary protein per day per pound of lean body mass, from 60 to 100 grams per day for most people. Exceed these minimums is certainly permissible, and people continue to lose weight consuming a 50% “surplus” over and above the minimum).

Now a new study in the medical journal Obesity sheds some new light on the power of protein. The Influence of Higher Protein Intake and Greater Eating Frequency on Appetite Control in Overweight and Obese Men studied both protein intake and frequency of eating:

Collectively, these data suggest that higher protein intake promotes satiety and challenge the concept that increasing the number of eating occasions enhances satiety in overweight and obese men.

Participants were given equal calorie diets, but one group had 79 grams of protein, and the other 138 grams of protein. One subset of each group was directed to eat 6 times a day, while another was served 3 meals per day.

This was a carefully controlled study, and did not test the participant’s ability to “stick to the diet” in a free-living arrangement. Lack of satiety is often a reason free living participants will cheat (and even some in carefully controlled ward studies find ways to cheat … even hospitals have vending machines). But in this study, the participants were fed controlled portions so all factors remain equal. Blood tests and surveys were used to determine several biochemical levels and how satisfied the participants were with the diet they were given.

There is enough variation in the small group to be uncertain if it proves anything in terms of blood glucose response (although several smaller meals seems to lead to better blood sugar levels). But one thing was consistent: higher protein intake provided a higher level of satiety. And frequent eating of smaller amounts did not provide more satiety; it provided less.

Protein and Food Consumption

I noticed when I adopted the The Protein Power Lifeplan
way of eating that I was finally able to eat regularly spaced meals without getting hungry between them. Prior to that, I can’t remember a time in my life when I wasn’t fighting the urge to snack between meals.

In dietary circles, the ability of food to satisfy your hunger is referred to as the satiety factor. Some researchers claim satiety is tied to the feeling of fullness you get from bulkier foods, but my experience is that high fiber foods do not necessarily satisfy my hunger. They make me feel full, but still hungry. There’s always room for another slice of that fiber-rich pumpkin pie.

Low carb advocates often cite the satiety factor of their diet, as I have done in the first paragraph. Some point to the higher percentage of fat in the diet than the typical low-fat diet emphasized by most doctors, making the claim that you cannot gain weight if you eat a low carb diet with plenty of fat. But some people do gain weight that way, so something else may be at work.

When I started Protein Power, I calculated my daily minimum protein requirement, as the book recommends. I was surprised at how much food I could eat. With 25 – 30 grams of protein per meal as a minimum, that meant a hearty bacon and eggs breakfast of 3 eggs (18 grams) and 3 slices of bacon (9 grams). My usual breakfast routine was a toasted bagel, then a snack before lunch because by 10 AM I was very hungry. But after eating the eggs and bacon mentioned above … I was full, and remained so until lunch time.

As the title of the book suggests, Protein Power is about getting the right amount of protein as well as reducing carbohydrates. It works for me. And it may be the protein that satisfies, rather than just the increased fat.

Nutritional ecologist Professor David Raubenheimer of New Zealand’s Massay University, recently conducted a study on primate eating habits in collaboration with other experts. Studying the Bolivian rainforest spider monkey, Professor Raubenheimer found the monkey’s food intake increased when low protein food sources were the only ones available.

The findings, published in the latest issue of the journal Behavioural Ecology, reinforce the theory that humans and other primates are physiologically predisposed to maintain a constant level of protein in their diets. But when the range of foods available to them is low in protein (yet high in fats and carbohydrates) they are compelled to eat greater quantities in order to maintain correct protein levels.

I think this explains the satiety issue better, and gives an indication of why some people experience weight gain even on a low carb diet. If they aren’t meeting their body’s protein requirements, they will be hungry. And hungry people eat more.