Mouse study suggests that eating a fatty breakfast and leaner dinner fights risk factors for heart disease and diabetes 04/30/2010
Ever heard the maxim, “Eat breakfast like a king, lunch like a prince, and dinner like a pauper?”
It’s been attributed to health-food pioneer Adelle Davis, but is probably a much older saying.
Whatever the real source, the results of a study in mice suggest that this advice may help to prevent metabolic syndrome… and the diabetes and heart disease that often follow.
People need some carbohydrates in the morning to provide a “wake-up” shot of glucose (blood sugar) to the brain and muscles.
But the new findings indicate that eating fewer carbs and more fat at breakfast may help prevent metabolic syndrome.
Metabolic syndrome is said to exist when you have any three of six different risk factors for diabetes and cardiovascular disease… including excess abdominal fat, high blood triglyceride levels, and glucose intolerance (i.e., insulin resistance).
The study was designed to measure the effects of two distinct diets on the development of metabolic syndrome in mice (Bray MS et al. 2010).
The animals were divided into two groups:
- The High-Carb Breakfast Group ate a higher-carb breakfast and a lower-carb, higher-fat dinner
- The High-Fat Breakfast Group ate a higher-fat breakfast and a lower-fat, higher-carb dinner
Importantly, the daily diets of the two groups contained the same number of calories and calories from fat. At the end of the study, the High-Fat Breakfast Group had normal metabolic profiles.
In contrast, the High-Carb Breakfast Group showed signs of metabolic syndrome, including weight gain, increased abdominal fat, glucose intolerance and more.
These differences were attributed to the fact that, compared with the High-Carb Breakfast Group, the mice in the High-Fat Breakfast Group were less likely to store dietary fat as unhealthful abdominal fat, which generates chemical signals that promote several other aspects of metabolic syndrome.
“The first meal you have appears to program your metabolism for the rest of the day,” said study senior author Martin Young, Ph.D. (UAB 2010)
What can people do?
These outcomes suggest that a breakfast of whole grain cereal or toast and fruit while generally healthful, may not be the healthiest possible daily choice.
Instead, it may be healthier to cut back on morning carbs and replace those calories with whole foods higher in fat and protein, including whole dairy foods (yogurt, cheese), fatty fish (salmon), high-omega-3 eggs… and/or an occasional bit of natural bacon from a humane, non-factory farm.
The findings make sense since a high-carb, low-fat breakfast would tend to trigger a spike in blood sugar.
In turn, a blood sugar spike early in the day can lead to carb cravings and chronically high blood sugar levels.
This is not to say that a breakfast of whole grain cereal and fruit is unhealthful… far from it.
Instead, these findings indicate that it may be better to include substantial fat at breakfast
Logically, the best choice would be a fatty fish, which will offer especially healthful proportions of the three major kinds of fat: omega-3, omega-6, and saturated.
(Omega-3s possess properties that seem to discourage weight gain and excess abdominal fat… see “Weight Loss Efforts Aided by Omega-3s,” which contains links to related reports.)
The fish highest in fat and omega-3s include (fresh or smoked) salmon, sardines, tuna, mackerel, and sablefish.
If you’d savor some sausage but don’t want pork or chicken—which possess inferior fat profiles, high in generally pro-inflammatory omega-6 fats—try wild salmon patties.
Tuna, sardines, and wild (not farmed) salmon (especially sockeye) are also the richest food sources of vitamin D – from 200 to 700 IU per 3 oz serving, versus the 100 IU in a glass of D-fortified milk.
What about the lean dinner eaten by the High-Fat Breakfast Group? If you eat a higher-fat breakfast should you avoid fat for dinner?
But it does seem to make sense to eat a fairly light dinner dominated by protein and vegetables rather than starches.
And it would be sensible to favor relatively lean protein foods that are higher in omega-3s and lower in omega-6 fats than meats and poultry… in other words, fish.
Study authors explain the implications for people
The study team was led by Molly Bray, Ph.D., professor of epidemiology in the University of Alabama at Birmingham (UAB) School of Public Health (Bray MS et al. 2010).
As she said, “Studies have looked at the type and quantity of food intake, but nobody has undertaken the question of whether the timing of what you eat and when you eat it influences body weight, even though we know sleep and altered circadian rhythms influence body weight” (UAB 2010).
Bray said the research team found that fat intake at the time of waking seems to turn on fat metabolism very efficiently and also activated the animals’ ability to respond to different types of food later in the day.
When the animals were fed carbohydrates upon waking, carbohydrate metabolism was stimulated and seemed to remain hyperactive even when the animal was eating different kinds of food later in the day.
Dr. Martin made a key point: “This study suggests that if you ate a carbohydrate-rich breakfast it would promote carbohydrate utilization throughout the rest of the day, whereas, if you have a fat-rich breakfast, you [would] transfer your energy utilization between carbohydrate and fat.”
In other words, a high-fat breakfast programs the body to more readily burn dietary fat for immediate energy needs.
Dr. Bray said the implications of this research are important for human dietary recommendations: “…if you really want to be able to efficiently respond to mixed meals across a day then a meal in higher fat content in the morning is a good thing” (UAB 2010).
She stressed that the animals in the High-Fat Breakfast group also ate a low-fat, low-calorie dinner, and thinks that combination is probably one key to the health benefits seen in those mice.
Bray and Young noted the need to test different types of dietary fats and carbohydrates to find the optimal mix, and to try a similar test in people.
As we noted above, omega-3s possess properties that seem to discourage weight gain and excess abdominal fat, so it would be smart to test a breakfast high in these fish-borne fats.
The Alabama team is now working on a study designed to determine how the two feeding regimens affect heart function.
- Bray MS, Tsai JY, Villegas-Montoya C, Boland BB, Blasier Z, Egbejimi O, Kueht M, Young ME. Time-of-day-dependent dietary fat consumption influences multiple cardiometabolic syndrome parameters in mice. Int J Obes (Lond). 2010 Mar 30. [Epub ahead of print]
- University of Alabama at Birmingham (UAB). Bacon or Bagels? Higher Fat at Breakfast May Be Healthier Than You Think, Says UAB Research. March 30, 2010. Accessed at http://main.uab.edu/Sites/MediaRelations/articles/75217/