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Adjusting the Way You Eat: Green, Yellow, and Red Light Foods
Posted: Aug 05, 2021
Adjusting the Way You Eat: Green, Yellow, and Red Light Foods  image

On May 28th, 2021, Dr. Natasha Wehrli joined the Nutrition and Wellness Chapter in the Myeloma Crowd Community to talk to us about imaging manifestations of common western diseases. A radiologist with strong interests in nutrition, Dr. Wehrli showed real images and shared real-life examples of people with common ailments such as liver, kidney, and gallbladder problems. Directly related to comorbidities caused by poor nutrition and lack of exercise, the images showed fatty deposits and blockages due to cholesterol build-up.  

Because of her strong interests in nutrition, Dr. Werhli decided to research what kind of diet or food choices would be appropriate for patients. What could alleviate their systems, or even possibly, reverse their disease? 

Dr. Wehrli is aware that an instant radical change in diet is not easy for most and is not recommended to occur overnight. But as her patients strive to adjust their diets to incorporate healthier foods over time, they are able to see successful results. I wanted to describe today what foods are recommended in a whole food plant-based diet and which foods should definitely be avoided. Because the food we eat is key to our culture and identity, changes like these can be incredibly hard to make. But when living with a disease, steps like these are crucial. 

Presented with a scale of red, yellow, and green light foods, Dr. Werhli shared information from about which foods are best for us, which we should limit, and which we should stop eating entirely. 

Note: Before changing your diet, please consult with your doctor. There may be certain foods that interfere with medications. 

First, let's clarify the classifications. 

Green-light foods should be favored. These include unprocessed plants foods. 

Yellow-light foods should be considered twice before we eat them. These include processed plants foods and unprocessed animal foods. 

Red-light foods should be heavily restricted or eliminated from your diet entirely. These include ultra-processed plant foods and processed animal foods. 

Now let's discuss the different foods that qualify within each category (while many will be specifically mentioned here, not all food items can be listed.) 

Green-Light Foods

These should be the predominant foods in your diet. An ideal diet would include several categories, one being 6+ servings of non-starchy vegetables. These foods have high dietary fiber, are packed with phytonutrients, and are very anti-inflammatory. Phytonutrients, or natural chemicals or compounds produced by plants, keep plants healthy by protecting them from insects and the sun. Phytonutrients also have antioxidant and anti-inflammatory properties that can help support a healthy human body. Their health benefits include eye health, immune health, protection against cancer and heart disease, and elimination of toxins in the body. 

These non-starchy vegetables and other beneficial "green-light" foods include but are not limited to: 

  • Kale 
  • Collard greens 
  • Spinach 
  • Arugula 
  • Swiss chard 
  • Bok choy 
  • Carrots 
  • Broccoli 
  • Cauliflower 
  • Asparagus 
  • Brussel sprouts 
  • Celery 
  • Mushrooms 
  • Onions 
  • Garlic 
  • Tomatoes 
  • Sugar snap peas 
  • Summer squash 
  • Bell peppers 
  • Artichokes 
  • Cabbage 
  • Cucumbers 
  • Shallots 
  • Eggplants 

Another category within the "green-light" foods is starchy vegetables. While the serving size of these types of vegetables is smaller than their non-starchy counterparts (2-4 servings a day), they are still categorized as foods we should be eating due to their high nutrient volume.  The benefit of these types of vegetables is that they provide healthy carbohydrates, fiber, and phytonutrients for us. 

A list of starchy green-light vegetables includes: 

  • Potatoes 
  • Yams 
  • Winter squash 
  • Corn 
  • Green peas 
  • Casssava 
  • Plantains 

Of course, whole fruits are recommended as well in whole food plant-based diet and are classified under the "green-light". It is recommended we eat 2-4 servings a day of whole fruits. Like other foods in their category, they provide fiber and phytonutrients for us as well. An interesting thing to note about whole fruits is that not all fruits are created equal or considered the same. As Dr. Wehrli puts it, "A banana is not going to pack the same punch as a blueberry." The more pigmented the berry, the better, though all have health benefits. 

A list of whole fruits you can and should include in your diet include: 

  • Apples 
  • Pears 
  • Oranges 
  • Bananas 
  • Strawberries 
  • Blueberries 
  • Raspberries 
  • Blackberries 
  • Grapes 
  • Mangoes 
  • Pineapples 
  • Kiwis 
  • Apricots 
  • Plums 

Of course, it wouldn't be a whole food plant-based diet without whole grains. A staple of the green-light food deck, whole grains should be an essential part of your diet. 5-8 servings of whole grains a day are recommended. True whole grains are a great source of fiber and protein, have been shown to lower cholesterol, and there are gluten-free whole grains for those on a celiac or gluten-restrictive diet. 

Whole-food grains that you can incorporate into your diet are: 

  • Whole wheat flour/pasta/bread
  • Barley 
  • Farro 
  • Brown Rice (GF)
  • Bulgar 
  • Amaranth (GF)
  • Quinoa (GF) 
  • Oats (GF) 
  • Rye 
  • Millet 
  • Sorghum (GF) 
  • Buckwheat (GF)
  • Teff (GF) 

Another green-light food category includes legumes and minimally processed meat alternatives (tempeh, tofu, and hummus). 2-5 servings of these types of food are recommended a day. Benefits include fiber, protein, minerals, and they also improve microbial diversity in the gut, which is incredibly crucial to gut and overall health. 

Foods in this category include: 

  • Kidney beans 
  • Black beans
  • Garbanzo beans
  • Pinto Beans 
  • Northern Beans
  • Adzuki Beans
  • Lentils 
  • Edamame 
  • Black-eyed peas 
  • Tofu 
  • Tempeh 
  • Hummus 

One of the more cautionary categories within the green-light foods are nuts are seeds, avocados, and whole coconuts. While filled with healthy fats, such as heart-healthy monounsaturated fats, this is not a food group worth indulging in for those that are wanting to lose weight. Snacking on nuts and seeds or including avocado in your meal can help with satiety. Going for the unsalted/unroasted version is obviously the healthiest, but even lightly salted nuts are healthier than processed snacks that you could be eating. 

Foods in this category include: 

  • Almonds 
  • Cashews 
  • Sunflower seeds 
  • Walnuts 
  • Pistachios 
  • Flaxseeds 
  • Chia Seeds 
  • Hemp seeds 
  • Peanuts (which is technically a legume)
  • Avocados 
  • Coconuts 

Greenish-Yellow Light Foods 

Somewhere in between the green and yellow classified foods lie dairy alternatives. While there are clean and beneficial plant-based dairy alternatives out there, there is a lot of variety when it comes to the production of these products. Dr. Werhli suggests that we make our own if/when possible or choose clean, organic brands. She notes that she personally chooses whole organic unsweetened soy milk and there are no emulsifiers (such as carrageenan) in it and cautions that we should be careful about which plant-based milk or dairy alternative we are choosing. Other cautionary ingredients or elements in common plant-based milk can be glyphosate (commonly found in non-organic oat milk and almond milk) or arsenic (rice milk). 

There are plenty of options however and they include: 

  • Soy milk 
  • Oat milk 
  • Almond milk 
  • Hemp milk 
  • Cashew milk 
  • Rice milk 
  • Coconut milk 

Yellow-Light Foods 

As we move onto the foods within the "yellow-light" classification, we see refined grains and fruit juices. Devoid of fiber, a necessary nutrient for our microbiome and gut health, their reputation also includes a high glycemic index. What happens is we consume these foods (white rice or pasta, for example), you don't have the benefit of the fiber, and your blood sugar spikes. 

Sugar-sweetened beverages fall within different categories, but fruit juice falls within the yellow-light zone. You may have some small benefits from the phytonutrients, but because the fiber is removed, according to Dr. Wehrli, your body doesn't treat it that much differently than it would Coca-Cola. 

A list of the foods in the yellow-light zone includes: 

  • White bread 
  • White rice 
  • White pasta 
  • Refined sugar 
  • Fruit juices 

Other yellow-light foods include refined vegetable oils containing mostly mono/polyunsaturated fats. These should be limited to 1 tbsp or less per day. These oils have a high-calorie content (which can lead to weight gain), are devoid of fiber, have high omega 6/3 ratio (which leads to inflammation) as well as possible endothelial dysfunction. 

Not all oils are made the same of course, and organic olive oil as a garnish or avocado or grapeseed oil as cooking oil are preferred over other oil options. 

Eggs and seafood are also considered yellow-light foods. While high in protein and potential sources of omega-3s, the quality of the product is all over the map for these foods. In addition, they contain a high choline content. Choline is a precursor to TMAO, which is associated with heart disease. Not to mention that our oceans are polluted and environmental contaminants can concentrate in the flesh. They can be a source of cholesterol and saturated fats. Farmed fish does not have omega-3's, nor fiber, and it's extremely low in antioxidants. 

Foods in this category that we should limit in our diet include: 

  • Eggs 
  • Salmon 
  • Crab 
  • Lobster 
  • Tuna
  • Shrimp 
  • Cod 
  • Tilapia 
  • Sea bass 
  • Oysters 

Other yellow-light foods include processed meat and dairy alternatives. You want to be wary of these because while eating a plant-based meat alternative is usually healthier for you than eating the meat itself, that doesn't necessarily make it healthy. These types of foods tend to be high in saturated fats and oils with added salt and/or sugar. 

A list of these foods include: 

  • Field Roast grain-based sausages 
  • Beyond Meat brand foods 
  • Impossible Foods 
  • Gardein meat alternatives 
  • Cheese, yogurt, and ice cream made from cashews, coconuts, etc. 

Low-fat dairy products are also to be limited. Although they are low in fat and contain protein and live cultures, they also cause lactose intolerance, galactose, animal protein (boosts IGF1- growth factor one, associated with cancer), estradiol, activates mTOR (linked acne and other inflammatory conditions), increases cholesterol, and contain no fiber, not to mention that most included large amounts of added sugar even when that sugar is unnecessary. 

Orange-Light Foods 

These include products containing coconut and palm oil. Although coconut and palm oil have received notice in the media for being "healthy foods", they are not. If they are solid oils at room temperature, Dr. Werhli notes, imagine what it's doing in your body. If it clogs your drain, do you really want to be putting it in your body? These types of foods are also stripped of fiber, contain or are saturated fats that drive up cholesterol. 

Chicken and poultry are also considered orange light foods. While considered the healthier of the meats, it is just as associated with cardiovascular disease as other meats. It has a lot of cholesterol, forms heterocyclic amines at high heat, dioxins, trans fats (banned in baked goods but naturally present in meat), and bacterial endotoxins. 

Red-Light Foods 

Foods in the Red-Light zone should be extremely limited or eliminated altogether from your diet. 

These foods are dangerous because they take all the risk factors from the other foods and concentrate them into one product. These risk factors are IGF1 (growth factor one linked to cancer), estrogens within the food, mTOR (linked to acne and inflammatory diseases), environmental pollutants, saturated and trans fats, little to no fiber, low antioxidants, added sugar, and the list continues. These foods are affecting our hormones, the way the gut functions, and so much more. If we really understood what these foods were doing to us, we would hopefully leave them and never pick them up again.

Foods we should significantly limit or strongly consider eliminating from our diet include: 

  • Doughnuts 
  • Cakes 
  • Cookies 
  • Cheese 
  • Fried Foods (especially fried seafood and meats) 

It's hard when the foods we are asked to eliminate are some of the most delicious- especially because they find a way into our culture, our daily lives, our very identity. But sometimes sacrifices must be made and adjustments need to take place in order to give our bodies a fighting chance. 

To finish off, if there was a list of foods that Dr. Werhli would strongly recommend we eliminate tomorrow, those foods would include: 

  • Ultra-Processed Meats 
  • Red Meats 
  • Sugar-Sweetened beverages 

These ultra-processed meats include nitrates, ammonia, and other processing chemicals. Red meats include harmful heme iron, Neu5gc, AGEs, and all of the other harmful elements we have mentioned throughout this article. Sugar-sweetened beverages such as soda are one the of most harmful things you can put into your body as they can deteriorate your bones, spike your blood sugar, and ruin your digestive tract. These foods have been directly linked to cancer formation in various studies. So why would we continue to put them in our body? 

Please give your body a fighting chance and make the choice to avoid: 

  • Deli meats/cold cuts 
  • Bacon 
  • Sausage 
  • Hot dogs 
  • Ground beef
  • Steak 
  • Ribs 
  • Lamb chops 
  • Soda 
  • Energy drinks with added sugars and artificial flavors 

For more information on Green, Yellow, and Red Light foods, as well as Imaging Manifestations in Common Western Diseases, please watch the recording of the event below: 

While a lot of information has been presented to you throughout this article, I hope you have been able to learn and identify which foods should be added to and eliminated from your current diet. By using these clear and easy-to-follow lists, you can make small necessary adjustments over time to improve your diet. Whether you are a myeloma patient, caregiver, or supporter of the community, making conscious choices to improve what you eat will not benefit you but many others within the community. A healthier community can get to a cure faster. Let's make small necessary changes to make that happen. 


Join our Nutrition and Wellness for Myeloma Chapter


As always, a big thank you to our Myeloma Crowd Community Sponsors who made the event with Dr. Natasha Wehrli possible. 


The author Audrey Burton-Bethke

about the author
Audrey Burton-Bethke

Audrey joined the HealthTree Foundation as the Myeloma Community Program Director in 2020. While not knowing much about myeloma at the start, she has since worked hard to educate herself, empathize and learn from others' experiences. She loves this job. Audrey is passionate about serving others, loves learning, and enjoys a nice mug of hot chocolate no matter the weather. 

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