April 17, 2013
Breakfast skipping compared to high protein breakfast: effect of appetite control in girls.

Are you a girl who regularly skips breakfast? Read on because this well-controlled study is for you.

Introduction:  Breakfast skipping is strongly associated with a greater chance of weight gain.  Furthermore, this trend is also linked to poorer food choices.  Higher protein meals are becoming more popular as a way to improve satiety and appetite control. The purpose of this study was to examine if it is better to skip breakfast or eat one higher in protein in regards to appetite control throughout the remainder of the day.

Methods:  Twenty overweight or obese girls between the age of 15-20 who normally skip breakfast were recruited for this study.  They were tracked for 7 consecutive days and randomized to one of 3 groups: breakfast skipping (BS), a normal cereal meal for breakfast (NP), or a high-protein breakfast (HP) consisting of beef and eggs for breakfast.  Breakfast and lunch were controlled but the rest of the day they were free to eat as much as they wanted. 

Results:  

  • NP & HP led to a 60% reduction in daily hunger.
  • HP lead to a greater increase in total fullness.
  • NP & HP led to a 30% reduction in daily desire to eat.
  • HP breakfast but not the others suppressed an important hunger stimulating hormone (ghrelin) by 20%.
  • HP breakfast but not the others increased an important satiety-stimulating hormone (PYY) by 250%.
  • BS & NP led to greater evening snacking than HP.

Discussion/Conclusion:  A small breakfast of merely 350kcal led to reductions in perceived hunger, the desire to eat, and prospective food consumption.  In addition, it also increased fullness.  What is even more interesting is that the high-protein breakfast group had additional benefits of a reduction in the hunger-stimulating hormone ghrelin, increases in PYY (a hormone that makes you feel fuller), and decreases in evening snacking, particularly of high-fat foods.  The authors note that a limitation of this study was that the breakfast skipping group and the high-protein group had similar total amounts of calories consumed during the day.  Although this study looked at 1-week of food consumption, it is not certain if eating a high-protein meal for longer periods of time (a year or more) would prevent weight gain.  

My input:  The most obvious inferences that the authors draw come from the simple fact that the breakfast skipping group is fasted.  Of course, their perceived hunger/fulness, desire to eat, and prospective food consumption will be higher in the morning because they just woke up.  I think the most powerful part of the study came from the blood draws and the actual measurable physiological significance that a high-protein breakfast did decrease a hormone responsible for making you want to eat and increase a hormone that tells your brain that you are full.That is what truly stands out as powerful rather than all the other results based solely on questionnaires.  For that reason, I’d suggest trying out the high-protein diet over your standard cereal-based breakfast and seeing how it works with your own feelings of satiety throughout the day.

Leidy et al Am J Clin Nutr. 2013 Apr;97(4):677-88

March 5, 2012
Early Stage Subcutaneous Adipose Tissue Remodeling

How would you like to be in a study where they fatten you up for 2 months?  Well, this group recruited volunteers just for that and have provided a significant advancement in what is known about adipose tissue structural changes during the first several weeks of weight gain.

Introduction:  The purpose was to examine molecular changes in adipose tissue structure after 2 months of an overfeeding protocol. 

Methods:  Forty-four healthy males were recruited and told to increase their daily caloric consumption to excess of 760 kcal/day.  To accomplish this, they added 100 grams of cheese, 20 grams of butter, and 40 grams of almonds to their usual diet.  Fat biopsies were taken at 2 weeks and again at the end of the 2 months.

Results:  MRI revealed a significant increase in abdominal tissue volume both for subcutaneous and visceral.  No changes in mean adipocyte (fat cell) surface size or number.  There was a significant increase in the density of capillary vessels.  As you would expect, there was an increase in the number of genes related to fatty acid and lipid biosynthesis.  There was also an upregulation in genes involved in formation of the extracellular matrix and angiogenesis (the creation of blood vessels).

Discussion/Conclusion:  Although there was an increase in genes responsible for storing excess fat, there was not yet a significant increase in size or number of fat cells.  Interestingly, there was an upregulation in capillary density and genes involved in creating more blood vessels to supply the adipocytes.  This could also be a reason why the extracellular matrix was remodeled to create space during initial weight gain.

My input:  There were also some other important molecular pathways that were downregulated in this study but for sake of boring you I decided to leave those out.  I think the main important finding in this study is the disovery of genes involved in creating new blood vessels for the fat cells.  It makes sense if you think about it, that an increase in adipose tissue would demand a larger supply of blood.  Therefore, it is necessary to increase the amount of vessels perfusing the cells.  This group did well in not only showing this in gene arrays but also in histological staining from the fat biopsies.   Another article from a different group found similar results in that the adipose tissue of obese and insulin resistant subjects had larger vessels but fewer capillaries when compared to lean subjects.  I would not be surprised to see pharmaceutical studies in the near future aiming at trying to reduce the amount of blood vessels as a way to amerilorate adiposity.  After that, I would not be surprised if that is soon the next gimmick in supplement companies’ “fat burners”/thermogenic products.

Alligier et al  J Clin Endocrinol Metab. 2012 Feb;97(2):E183-92.

February 6, 2012
One final important remark while looking at fructose is that it has been shown to increase visceral adiposity whereas glucose has been shown to increase sub-cutaneous adiposity.  I don’t think it is necessarily true that one can lead to more storage than the other in the long-term but so far the data trends toward that direction.
Looking at two studies with markers than can lead to increases in fat stores, the first shows that with 42 studies between the years 1966 and 2006, fructose has no effect on:
 body weight with less than 100 grams ingestion per day
fasting triglyceride with less than 100 grams ingestion per day
post-prandial (after eating) triglycerides with less than 50 grams ingestion per day
The second review with 16 reports between the years 1950-2010 states that fructose does increase plasma triglycerides when given with hyper-energetic (overeating) than iso-energetic diet (balanced).  So we have a mix of conclusions.
From these you think you could get away with 1 can of soda per day.  Maybe that is true but don’t forget the short-term studies I posted that have shown deleterious effects, even as short as three weeks, with ingestion of fructose.  Why risk it if it is something you can live without and is not a necessary molecule to ingest in extra amounts?
Since I didn’t get to post last week on it, the sugar month theme will be finished by the end of this week so make sure to check back soon to see the conclusions.  After that, tons of new articles to post on a variety of topics.

One final important remark while looking at fructose is that it has been shown to increase visceral adiposity whereas glucose has been shown to increase sub-cutaneous adiposity.  I don’t think it is necessarily true that one can lead to more storage than the other in the long-term but so far the data trends toward that direction.

Looking at two studies with markers than can lead to increases in fat stores, the first shows that with 42 studies between the years 1966 and 2006, fructose has no effect on:

  •  body weight with less than 100 grams ingestion per day
  • fasting triglyceride with less than 100 grams ingestion per day
  • post-prandial (after eating) triglycerides with less than 50 grams ingestion per day

The second review with 16 reports between the years 1950-2010 states that fructose does increase plasma triglycerides when given with hyper-energetic (overeating) than iso-energetic diet (balanced).  So we have a mix of conclusions.

From these you think you could get away with 1 can of soda per day.  Maybe that is true but don’t forget the short-term studies I posted that have shown deleterious effects, even as short as three weeks, with ingestion of fructose.  Why risk it if it is something you can live without and is not a necessary molecule to ingest in extra amounts?

Since I didn’t get to post last week on it, the sugar month theme will be finished by the end of this week so make sure to check back soon to see the conclusions.  After that, tons of new articles to post on a variety of topics.

January 16, 2012
Simple but powerful thought of the week.

A change in weight of 1 kg results in approximately 1 mmHg change in systolic and diastolic blood pressure.  Don’t let it pile on.

Neter et al Hypertension. 2003 Nov;42(5):878-84

January 14, 2012
Low to moderate sugar-sweetened beverage consumption impairs glucose tolerance and lipid metabolism and promotes inflammation in healthy young men: a randomized controlled trial.

Continuing with sugar month, here is a decent study looking at practical consumption of sugar-sweetened beverages (SSBs).  By practical, I mean amounts that are equivalent to how much one would consume on average/day.  That is the main appeal here. 

Introduction:  The aim of this study was to investigate the effect of five different SSBs containing fructose, glucose, and sucrose, in amounts likely to be consumed in everyday life and over a limited period, on lipid and glucose metabolism with an emphasis on LDL particle size and inflammatory makers in healthy young men.  Wow, that was a long sentence.

Methods:  As to not be bias, my last post was all with women subjects, now this one is all with normal weight men, 29 of them age 25-50.  The protocol was a randomized crossover of 6 different groups; medium fructose, sucrose and glucose (40 g/day), high fructose, sucrose, and glucose (80 g/day).  Converted in liters, the amount of sugar was 66.5 g/L for the medium drinks and 133.5 g/L for the high drinks and these were consumed with the three main meals of the day for there weeks with a 4-week washout period before entering another group.

Results:  Waist-to-hip ratio was significantly higher in all interventions containing fructose, a significantly higher percentage body fat in the high fructose intervention than in the high glucose, and finally a significantly higher waist circumference in the high sucrose compared to the high glucose group.  LDL particle size decreased significantly only after the high fructose and high sucrose interventions.  A marker for inflammation, hs-CRP, increased significantly after all interventions but the highest after high fructose ingestion.  Comparing the first intervention to the final, there was a significant increase in waist-to-hip ratio and in fasting glucose.

Discussion/Conlusion:  The real intriguing finding of this study was that even with moderate (just 6.5% of subjects daily energy intake) consumption of SSBs everyday for only 3 weeks, adverse effects existed in regards to LDL particle size and distribution, waist-to-hip ratio, fasting glucose, and inflammatory markers.

My input:  The researchers state it best with the main limitation in the study; the actual amount of sugar used was analogous to everyday ingestion; however, the sugar composition itself was not.  When you drink soda or other sweetened beverages, they are always a mix of sugars (fructose or glucose) and not solely one like in this study.  Therefore, the group that would be closest to real-life scenarios would be the sucrose group.  However, this limitation can be downplayed by the fact that it is important for researchers to understand how one sugar reacts in the body over a period of time.  The waist-to-hip ratio difference was small, but it is still significant nonetheless. Three weeks is a short period of time, and it would be interesting to see if waist circumference would increase more after a longer intervention.  Although, they did reach significant differences from baseline in other negative health factors as well.  I hope this has you rethinking those sugary drinks, especially if it is an everyday habit.


Aeberli et al Am J Clin Nutr. 2011 Aug;94(2):479-85

January 5, 2012
Here is a very interesting figure published in Diabetologia last month showing that across all age ranges, men (the black dots) develop Type 2 Diabetes at a lower BMI than women.  The means were 31.83 kg/m(2) (SD 5.13) in men and 33.69 kg/m(2) (SD 6.43) in women polled from 51,920 men and 43,137 women.  Now that’s a strong sample size.  It is very important to note that it is only Caucasians that were reported here and this may be different for other ethnic groups.
Diabetologia. 2011 Dec;54(12):3003-6.

Here is a very interesting figure published in Diabetologia last month showing that across all age ranges, men (the black dots) develop Type 2 Diabetes at a lower BMI than women.  The means were 31.83 kg/m(2) (SD 5.13) in men and 33.69 kg/m(2) (SD 6.43) in women polled from 51,920 men and 43,137 women.  Now that’s a strong sample size.  It is very important to note that it is only Caucasians that were reported here and this may be different for other ethnic groups.

Diabetologia. 2011 Dec;54(12):3003-6.

June 30, 2011
Diet Soda, not so good afterall.

Epidemiologists from the School of Medicine at The University of Texas Health Science Center San Antonio reported data showing that diet soft drink consumption is associated with increased waist circumference in humans, and a second study that found aspartame raised fasting glucose (blood sugar) in diabetes-prone mice.

"Data from this and other prospective studies suggest that the promotion of diet sodas and artificial sweeteners as healthy alternatives may be ill-advised," said Helen P. Hazuda, Ph.D., professor and chief of the Division of Clinical Epidemiology in the School of Medicine. "They may be free of calories but not of consequences."

Diet soft drink users, as a group, experienced 70 percent greater increases in waist circumference compared with non-users. Frequent users, who said they consumed two or more diet sodas a day, experienced waist circumference increases that were 500 percent greater than those of non-users.

Click to read more.