Saturday, July 13, 2019

Does skipping breakfast make it harder to lose weight?

The Study
For decades, people trying to lose weight have been told that skipping breakfast will seriously hurt their efforts. A recently published meta-analysis put this theory to the test. A meta-analysis combines the findings from several trials and produces a summary estimate of the results. This particular meta-analysis included 13 randomized trials. The results were both interesting and surprising. There was a slight weight loss benefit to skipping breakfast. Subjects randomized to a breakfast skipping group lost about 1 pound more than subjects randomized to a breakfast eating group. The breakfast skippers also had an average of 260 fewer calories consumed per day. British Medical Journal 2019; 346:142.

Take Home Message
Before we all start skipping breakfast, lets take a deep breath. While this study is interesting, the trials only lasted between 24 hours and 16 weeks. This is a very short time for weight loss studies. If there was a drop in resting metabolic rate with skipping breakfast, it may not appear until after this amount of time. In fact, this paper mentions that longer term observational studies have shown a weight loss benefit to eating breakfast.

Despite these interesting results, I still recommend eating breakfast for the following reasons:

-If you eat dinner at 6 in the evening, skip breakfast the next morning and have lunch at noon, you have gone 18 hours without food. My concern with this amount of time fasting is that your body will go into starvation mode and start to reduce resting metabolic rate. There is evidence in the research literature that fasting can decrease resting energy expenditure, as well as have a number of other effects that decrease weight loss efficacy. (Take a look at some of this research here)

-If you are only eating twice per day, it is really hard to get enough protein, healthy fats, fruits, vegetables, vitamins and minerals.

-Your mood, focus, energy and attention will be better if you eat breakfast. 

There are lots of good reasons to eat breakfast. Although this is a very interesting study, I wouldn’t let it change your mind about the importance of this meal.

Is snacking a good idea if you are trying to lose weight?

The Study
Many of my weight loss clients ask me if they are permitted to snack if they get hungry in between meals. A recent study published in the American Journal of Clinical Nutrition examined the impact of snacking on total daily calories. In this investigation, 3,777 men and women from the National Health and Nutrition Examination Survey were studied. These subjects each filled out two 24-hour dietary recalls. In one of the recalls, the subject reported snacking in between meals. In the other, they did not. Total calories were compared between the two days.

On the days that the men snacked, they consumed an extra 239 calories. The women consumed an extra 219 calories on the day that they snacked. Added sugars and sodium were significantly higher on the days that included snacking. American Journal of Clinical Nutrition 2019;109:1145-53.

Take Home Message
I have never been a big fan of snacking for my weight loss clients. If you are eating 3 good, blood sugar stabilizing meals each day, there is really no need to snack. You should not be at all hungry in between meals. The additional calories that snacking adds can have a dramatic impact on body weight. The 200 plus extra calories found in this study would result in nearly two pounds gained each month. 

Eat three balanced meals that include a healthy source of fat, protein and low glycemic carb. You won’t be hungry in between meals and it will be much easier to lose weight.

New research on eggs and cardiovascular disease

Eggs are back in the news in a big way after a meta-analysis published in April in the Journal of the American Medical Association showed an increased risk of cardiovascular disease with only ½ egg consumed per day. Should this study lead us to alter our consumption of eggs? Let’s take a closer look.

The Article
The meta-analysis included 29,615 participants from 6 prospective U.S. cohorts that were followed for roughly 18 years (Reference 1). Each additional half egg consumed per day was associated with a 6% higher risk of cardiovascular disease and an 8% higher risk of mortality.

Limitations And Other Research
While this is definitely an interesting study and we must consider the findings, there are two reasons not to go completely overboard and swear off eggs completely.

#1: There are some methodological issues with this study. To start with, only a single measure of egg consumption was taken and then subjects were followed for 18 years. There is a really good chance that egg consumption changed during this time. Very few of us eat the same way for 18 consecutive years. This study did not account for changes in diet over the follow-up.

Another methodological issue is that the control of confounders was not ideal. A confounder is a variable that may impact risk of cardiovascular disease. To deal with a confounder, you measure it and then control for it in statistical models. Similar to egg consumption, confounders in this study were not updated, just a baseline measure was used. This leaves the door open for residual confounding. Further, certain confounders were left out of the models, including family history of cardiovascular disease, menopausal status and supplement use.

#2: Other studies that were better executed do not show an increased risk of cardiovascular disease with a high consumption of eggs. For example, in an analysis of the Nurses’ Health Study and the Health Professional Follow-up Study that included 117,933 men and women, no significant association was found between consumption of one egg per day and risk of heart disease or stroke (Reference 2). In this study, both egg consumption and confounders were repeatedly updated during the follow-up period. There was also a more complete control of confounders.

Another very large meta-analysis was conducted a few years back (Reference 3). This analysis included subjects taken from 22 cohorts with a follow-up of up to 20 years. When comparing subjects who consumed one or more eggs per day to subjects consuming less than 1 egg per week, there was no increased risk of heart disease, stroke or total cardiovascular disease.

Conclusions And Recommendations
While the results of this new study need to be considered, a lot of other well-designed research has shown that eggs are safe to consume. If you are otherwise healthy, a moderate consumption of eggs can be considered part of a healthy diet. Keep in mind that eggs are a really good source of protein, healthy fat, vitamins and minerals. The yolks are very much like a multivitamin pill.

If you have diabetes, talk to your doctor about how many eggs you should consume, as some research has shown an increased risk of cardiovascular disease with high egg consumption in diabetics.

1) Zhong VW, et al. Association of dietary cholesterol or egg consumption with incident cardiovascular disease and mortality. Journal of the American Medical Association 2019; 321:1081-95.

2) Hu FB, et al. A prospective study of egg consumption and risk of cardiovascular disease in men and women. Journal of the American Medical Association 1999; 281:1387-94.

3) Shin, et al. Egg consumption in relation to risk of cardiovascular disease and diabetes: A systematic review and meta-analysis. American Journal of Clinical Nutrition 2013; 98:146-59.