Nutrigenomics – Connecting The Link Between DNA, Nutrition & Your Goals

Anyone who has ever struggled to lose weight or achieve another fitness goal, knows that there is no single best diet or nutritional plan that works for everyone. We are unique and require an individualized approach

A big reason for that is our individual genetic makeup. With modern technology we can now take simple tests for specific genes. This information helps explain some of the struggles people experience regarding nutrition, health, and weight.

Everyone has a unique genome that impacts everything from how we utilize protein and fat to whether we absorb enough iron from the foods we eat. Knowledge of these individual differences is a powerful tool.

If you, or someone you know, is interested in taking health or fitness DNA tests for personalized reports, it’s important that you know what to do with the results. Find out what these reports tell you about your nutritional or exercise needs and limitations and how to use that information for their benefit.

DNA and Nutrition – What is Nutrigenomics?

Being able to look at an individual’s genetic makeup is now less expensive and more accessible than ever. Any one of our clients can get a test done that looks specifically at how their genes impact nutrition, health, fitness, body composition, and more.

Nutritional genomics, or nutrigenomics, is the study of the interactions between an individual’s DNA, nutrition, and health. It can also be a more general study of the overall human genome and nutrition. Researchers in this field look at how foods and nutrients impact human genetics and how genes inform the body’s response to nutrients.

How Does Genetics Affect Nutrition? And How Can That Help You?

While researchers are working to uncover generalities about the human genome and nutrition, it is also possible to get individualized data. For all of us, it is this personalized information—how one or more genes or mutations in genes impact how we absorb micronutrients, gain weight, or utilize macronutrients—that is important.

With a fitness and nutrition DNA report, we can pick out the information that will help determine goals and strategies for meeting them. Personalized genetic information will help you:

  • Set goals that are more reasonable for you
  • Recommend macronutrient ratios that make sense for a healthy weight and body composition
  • Create nutritional plans that consider vitamin or mineral processing or uptake issues
  • Create a workout and diet plan for more effective weight loss

DNA Tests and Nutrient Utilization

Your DNA-based nutrition report will include a lot of information about how you utilize nutrients, including macronutrients, vitamins, and minerals. Genetic differences can lead to variations in how these nutrients are absorbed, how they are used, proportions and amounts that maximize health and wellness.

Macronutrients

Weight loss and maintenance, energy utilization, athletic performance, and more depend on how we consume and utilize proteins, fats, and carbohydrates. Most recommendations for macronutrient proportions are generalized, but DNA tests inform more personalized macro ratios.

  • For people who have a normal genotype for protein utilization. Their ability to lose weight will not depend on protein intake. The less common enhanced genotype means that an individual will be able to lose weight more effectively and efficiently with a higher proportion of protein in the diet.
  • Dietary Fats. Most people fall into the normal category for fat utilization. Their weight loss seems to be independent of the percentage of fat in the diet if calorie intake is reasonable. Those who test for the “highly sensitive” genotype should consume a smaller proportion of fat and replace saturated fat with MUFAs. Olive oil, avocadoes, hazelnuts, and almonds are high in MUFAs. This will aid in weight loss and maintenance.
  • Dietary Carbohydrates. For carbohydrate utilization, people can be “low sensitivity”, “medium sensitivity” and “high sensitivity.” Those in the “low sensitivity” category will see no major differences in weight loss based on carb proportions. The “medium” or “high sensitivity” means that a person benefits from eating better quality carbs. These should be complex carbs, like whole grains and beans. In the high and medium categories, people should eat fewer carbs and be especially careful to avoid starchy foods and processed grains, such as potatoes and white bread while limiting added sugars to no more than 25 grams(100 calories) daily. The glycemic index is a good tool to help you choose better carb sources.

Micronutrients

Less important for weight loss, but still crucial for overall health, is information on micronutrient utilization. Most health and fitness DNA tests provide data on Vitamins A, B6, B9 (folate), B12, D, and E as well as risk of inflammation, that might suggest an omega-3 supplement which can be especially useful.

Certain genotypes can tell you if your are absorbing and utilizing these nutrients adequately. This is important to know for health but can also be useful for nutrition and weight goals. For instance, some people have a genotype indicating increased requirements for B12, which means they tend to be deficient. Low levels of B12 cause a type of anemia, called pernicious anemia. This can lead to serious health risks and make working out more difficult due to fatigue.

A common variant in the MTHFR genotype has been associated with lowered folate and elevated homocysteine levels in the blood. You may need to increase folate levels in your diet by consuming more beans, lentils, spinach, asparagus, and avocados. Supplementing with activated methyl-folate will be more effective where as folic acid in some cases may be toxic.

One of the best ways to ensure an adequate intake of micronutrients, both vitamins and minerals, is to eat a diet rich in a variety of vegetables. We talk with our “bitter taster” clients about how important this is for health and weight maintenance.

Nutrition and Genetics and the Impact on Disease Risk and Health

Of course, DNA reports for nutrition are important for more than simply meeting weight loss goals. Clients also come looking for advice on a healthy diet to avoid disease and to live well. These reports are packed with different types of information to help advise you more effectively.

How Does Genetics Affect Nutrition and Health Measures? 

Certain health measures, like cholesterol, are impacted by genetics as well as diet. For instance, you may have a “sensitive” or “highly sensitive” genotype for cholesterol response to dietary fat. This means your cholesterol levels tend to increase more rapidly with fat intake as compared to someone with the “low sensitivity” genotype. In this case you may need to be more careful about the fat content in your diet.

Diabetes is a major public and individual health problem in the U.S. Understanding insulin sensitivity and response can help you make better food choices to control blood glucose levels.

Polyunsaturated fats, like omega-3 fatty acids and alpha-linoleic acids, are the so-called healthy fats. The body does not make these fats, so how much a person has in their bloodstream largely depends on diet. Some genes, however, also make an impact. Although common, the “normal” genotype for this is not ideal. Clients with this result really need to focus on adding healthy fats to their daily meals.

This Is Not Medical Advice

Your DNA report can be used to help guide nutrition choices, however it is not  providing medical advice.  Always follow the guidance of your doctor or medical professional treating any and all medical advice. This is especially true as it relates to health risks and chronic disease.  Guidance can absolutely be provided on how to plan and eat a healthy diet for both weight goals and overall health and wellness.

The use of individualized DNA reports is poised to revolutionize health, wellness, and fitness. As a Nutrition Coach we are excited to be a part of this big change. We enjoy providing more personalized, molecular, and genetic information for each client and help you adapt your lifestyles, diets, and fitness routines for better results. We help you understand these reports and how to use them.

Clients today expect their trainers and nutrition coaches to be up to date on all the related science, including genomics. We are excited to provide this service to better help you accomplish your goals.

The Right Rest For Your Goals

Rest periods between sets is an integral and often overlooked contributor to the success of any strength training program. Chances are, you are not optimizing this crucial variable. So what is the trick to get the most out of your rest? Well, it depends on your training goals and level of conditioning. Optimal rest periods between sets can vary from 30 seconds or less up to 5 minutes! We know that it takes 2.5 to 3 minutes for the phosphagen (Creatine Phosphate/ATP) stores to fully recover from a set of intense exercise 1. Contrary to what you might think, resting for this time period to allow complete phosphagen recovery is not optimal for all athletes. Let’s take a look at some of the facts about rest intervals. I have grouped the information by training goals in order to make it more reader-friendly.

Absolute Strength Athletes

First, let’s define who you are. You are training for explosive, low repetition activities of short duration. Muscle hypertrophy and endurance are not your primary concerns. Weightlifters, powerlifters, sprinters, football players, sprint cyclists and any other athletes in a sport emphasizing high intensity/short duration activities, this is you!

Your optimal rest period range between sets is 3 to 5 minutes. One reason for this longer rest is to allow full phosphagen recovery before you begin the next set. Full recovery allows you to produce the greatest muscular force possible for each set performed, and thus receive the greatest absolute strength gains from your training. Another good reason for this rest interval is that when combined with heavy training loads, it appears to produce greater testosterone levels in experienced strength athletes incorporating large muscle group exercises in their training 2. A higher testosterone level equates to greater gains in strength.

Hypertrophy and Endurance Athletes

Who are you? You are an athlete training for muscular size and/or to increase your ability to apply near maximal muscular force over a time period. Bodybuilders, fitness buffs, long-sprint runners/swimmers/cyclists, wrestlers, soccer players, and sports similar in intensity, this is you!

Your optimal rest period range is 30 to 60 seconds. Another way to look at this is to shoot for a work-rest ratio of 1:1. This means that you spend the same amount of time resting as it took you to complete the previous set. Athletes whose sport demands 1 to 3 minutes of all out effort with little or no rest may benefit from a work-rest ratio of 1:1 or slightly higher. This means that you spend the same or less time resting than you do performing each set of exercise 1. In either case, the principles behind the practice are the same.

Using this rest interval between sets creates high lactate levels in the exercising muscles 3. This forces the body to improve its ability to buffer the accumulating lactate, thereby improving your ability to sustain moderate, near maximal or maximal contractions over a given time period. High volume, short rest period training has also been found to increase human growth hormone levels when compared to training with longer rest periods 2. In addition, muscular hypertrophy (growth in size) will be maximized using the 1:1 work-rest ratio in conjunction with high training volume and a weight load between your 8 and 12 repetition maximum 1.

Special Considerations

Keep in mind that whatever you are training for, beginners need more rest between sets then the seasoned veterans. If you are just starting out, stay in the conservative end of your range. If you are experienced you will benefit more from a shorter rest period. In addition, athletes coming back from periods of detraining due to injury or otherwise should increase the amount of rest between sets until you are back in your normal physical condition.

The Unique Case of Circuit Training

Traditional circuit training incorporates a rest period of typically less than 30 seconds, or a work-rest interval a fair margin greater than 1:1. So where does this fit into an athlete’s training? One has to understand that circuit training is designed to provide a happy medium between strength and aerobic training. Due to the short rest interval between sets, strength gains are less than optimal with circuit training (30 to 50% less) when compared to traditional strength training 1. However, modest gains in aerobic capacity can be achieved. So who benefits from circuit training? Athletes that require a balance of both strength and cardiovascular endurance for their sport, athletes and fitness buffs with limited time and anyone wishing to add variety to their training would all benefit from circuit training.

In conclusion

No matter what your sport or fitness passion may be, understanding the science of rest between sets will put you in the driver’s seat on the road to your training goals. As you can see, not all athletes benefit from waiting the full three minutes for complete phosphagen recovery. Different periods of rest can produce very specific results. It is up to you as the athlete to decide which approach will be of greatest benefit to you.

  1. Fleck, S.J., and W.J. Kraemer. . Champaign, IL: Human Kinetics. 1987.
  2. Kraemer, W.J. Endocrine responses and adaptations to strength training. In: Strength and Power in Sports, P. Komi, ed. Oxford: Blackwell Scientific. 1992. pp. 291-304.
  3. National Strength and Conditioning Association, Essentials of Strength Training and Conditioning. Champaign, IL: Human Kinetics. 1994.