Study: Ultra-Processed Diets Cause Excess Calorie Intake And Weight Gain

What would happen if you put some people on a diet of mostly ultra-processed food (NOVA Group 4 from my previous post) and compared them to a group of people who ate less processed foods (mostly NOVA Group 1)?

That’s what Kevin Hall did in his recent study:

Ultra-Processed Diets Cause Excess Calorie Intake And Weight Gain: An Inpatient Randomized Controlled Trial Of Ad Libitum Food Intake, Cell Metabolism, 16 May 2019

  • 20 inpatient adults (mean age: 31 yrs) received ultra-processed and unprocessed diets for 14 days each (crossover design).
  • Diets were matched for presented calories, sugar, fat, fiber, and macronutrients.
  • Ad libitum intake (consume as much or as little as desired) was ∼500 kcal/day more on the ultra-processed versus unprocessed diet.
  • Weight changes were highly correlated with energy intake with participants gaining 0.9 kg (2 pounds) during the ultra-processed diet and losing 0.9 kg (2 pounds) during the unprocessed diet.

People gained 2 pounds in 2 weeks on the ultra-processed diet (and lost 2 pounds in 2 weeks on the less-processed diet). They gained weight because they ate more. They ate more because ultra-processed food is designed to be hyperpalatable:

[Hyperpalatable] foods are deliberately engineered in such a way that they surpass the reward properties of traditional foods, such as vegetables, fruits, and nuts. Food chemists achieve this by suffusing products with increased levels of fat, sugar, flavors, and food additives.

This is how the authors desribed it:

Ultra-processed foods may facilitate overeating and the development of obesity because they are typically high in calories, salt, sugar, and fat and have been suggested to be engineered to have supernormal appetitive properties that may result in pathological eating behavior. Furthermore, ultra-processed foods are theorized to disrupt gut-brain signaling and may influence food reinforcement and overall intake via mechanisms distinct from the palatability or energy density of the food.

This small study was the first randomized, controlled study to compare ultra-processed with less-processed foods. It’s likely more studies will follow because:

The rise in obesity and type 2 diabetes prevalence occurred in parallel with an increasingly industrialized food system characterized by large-scale production of high-yield, inexpensive, agricultural “inputs” (primarily corn, soy, and wheat) that are refined and processed to generate an abundance of “added value” foods. Ultra-processed foods have become more common worldwide, now constitute the majority of calories consumed in America, and have been associated with a variety of poor health outcomes, including death.

Two other mechanisms I’ve reported in the past that could cause people to gain weight on ultra-processed foods that don’t have anything directly to do with nutrients are:

1. Food Texture: I just reposted the study about rats that gained more weight eating soft pellets instead of hard pellets, same calories.

2. Food Combination: The combination of high fat and easily digested carb in a meal can, over time, contribute to weight gain, glucose dysregulation, and other metabolic disorders.

My feeling about this study … I like it but it’s more a technology demonstrator than a plan for how to eat. I just don’t see people eating mostly NOVA Group 1 (unprocessed and minimally-processed foods). For one thing, unprocessed food costs more.

The weekly cost for ingredients to prepare 2,000 kcal/day of ultra-processed meals was estimated to be $106 versus $151 for the unprocessed meals as calculated using the cost of ingredients obtained from a local branch of a large supermarket chain.

It’s not just the cost of the food that’s a barrier. Labor required to eat this way, a whole-foods diet, is considerable. I’ve said this. Hall says it too:

Policies that discourage consumption of ultra-processed foods should be sensitive to the time, skill, expense, and effort required to prepare meals from minimally processed foods—resources that are often in short supply for those who are not members of the upper socioeconomic classes.

If you pick the study link up top and click “Supplemental Materials” under “Method Details” and “Diets” you can see photos of the actual meals used in the metabolic ward in the study. I learned a lot from these. For instance, here’s an ultra-processed dinner:

Ultra-processed Menu, Day 1, Dinner: Steak (Tyson), Gravy (McCormick), Mashed potatoes (Basic American Foods), Margarine (Glenview Farms), Corn (canned, Giant), Diet lemonade (Crystal Light) with NutriSource fiber, Low fat chocolate milk (Nesquik) with NutriSource fiber.

At first glance it didn’t look very processed to me, just a potato that was mashed, some whole kernel corn, and slices of beef.

I looked it up:

Tyson Beef Steak Strips:
Ingredients: Beef steak strips, water, contains 2% or less of the following: beef fat, brown sugar, canola oil, dried beef broth, kiwi powder, maltodextrin, natural flavor, natural smoke flavor, salt, spices, yeast extract. GLAZED WITH: Canola oil, corn starch, guar gum, maltodextrin, natural flavors, natural smoke flavor, olive oil, salt, spice, sunflower oil, water, xanthan gum, yeast extract.

Sugar inside the meat? And lots of other ingredients. Definitely counts as NOVA Group 4.

Basic American Foods, Mashed Potatoes:
Ingredients: potato, salt. freshness preserved with sodium bisulfite

It wasn’t a fresh potato, maybe dried granules and salt and what looks like a preservative. Yep, NOVA Group 4.

I couldn’t find Giant (not Green Giant) canned corn but I think it’s unfair to call whole corn kernels ultra-processed even if they had salt added. They allow pasta in the unprocessed menu and that’s a more processed food to me.

Here’s the unprocessed dinner for comparison:

Unprocessed Menu, Day 1, Dinner: Beef tender roast (Tyson), Rice pilaf (basmati rice (Roland) with garlic, onions, sweet peppers and olive oil), Steamed broccoli, Side salad (Green leaf lettuce, tomatoes, cucumbers) with balsamic vinaigrette (balsamic vinegar (Nature’s Promise), Orange slices, Pecans (Monarch), Salt and Pepper (Monarch)

Holy Cow, the effort involved in putting that on the table at the end of a work day!  I saw that he served black beans several times a week, made from scratch using dried beans. Cooking black beans from scratch takes a long time, I can attest, as does cooking whole farro or whole barley which he also serves.

Here are some news summaries:
Processed Foods Are Bad For Weight Loss, Study Shows, Consumer reports, 16 May 2019
Processed Foods Lead To Weight Gain, But It’s About More Than Calories, Medical News Today, 17 May 2019
Ultra-Processed Foods Make Us Eat More, and It’s Not About Their Nutritional Makeup, PBS, 16 May 2019
Why Eating Processed Foods Might Make You Fat, New York Times, 16 May 2019
The NIH Director’s blog: Ultra-Processed Diet Leads To Extra Calories, Weight Gain, Dr. Francis S. Collins, NIH Director, 21 May 2019

Processed Food: Breaking It Down

Most of the food we eat is processed to some degree. Processed food is not unhealthy. It is, in fact, the food we evolved to eat. But modern methods of food processing have turned modern processed food into a wasteland.

A new food classification system was developed, called NOVA (not an acronym), that categorizes foods according to extent and purpose of food processing.

Food Classification, Public Health. NOVA. The Star Shines Bright., World Nutrition, January-March 2016

The following descriptions are from Open Food Facts, a food products database that defines a food by its NOVA group, among other things. It’s open source, global, and still adding foods. A great resource. The definitions in the NOVA document above are more extensive and include examples.

Nova Groups For Food Processing: A Classification In 4 Groups To Highlight The Degree Of Processing Of Foods

Group 1 – Unprocessed or minimally processed foods
Group 2 – Processed culinary ingredients
Group 3 – Processed foods
Group 4 – Ultra-processed food and drink products

Group 1. Unprocessed Or Minimally Processed Foods

Unprocessed (or natural) foods are edible parts of plants (seeds, fruits, leaves, stems, roots) or of animals (muscle, offal, eggs, milk), and also fungi, algae and water, after separation from nature.

Minimally processed foods are natural foods altered by processes that include removal of inedible or unwanted parts, and drying, crushing, grinding, fractioning, filtering, roasting, boiling, non-alcoholic fermentation, pasteurization, refrigeration, chilling, freezing, placing in containers and vacuum-packaging. These processes are designed to preserve natural foods, to make them suitable for storage, or to make them safe or edible or more pleasant to consume. Many unprocessed or minimally processed foods are prepared and cooked at home or in restaurant kitchens in combination with processed culinary ingredients as dishes or meals.

Group 2. Processed Culinary Ingredients

Processed culinary ingredients, such as oils, butter, sugar and salt, are substances derived from Group 1 foods or from nature by processes that include pressing, refining, grinding, milling and drying. The purpose of such processes is to make durable products that are suitable for use in home and restaurant kitchens to prepare, season and cook Group 1 foods and to make with them varied and enjoyable hand-made dishes and meals, such as stews, soups and broths, salads, breads, preserves, drinks and desserts. They are not meant to be consumed by themselves, and are normally used in combination with Group 1 foods to make freshly prepared drinks, dishes and meals.

Group 3. Processed Foods

Processed foods, such as bottled vegetables, canned fish, fruits in syrup, cheeses and freshly made breads, are made essentially by adding salt, oil, sugar or other substances from Group 2 to Group 1 foods.

Processes include various preservation or cooking methods, and, in the case of breads and cheese, non-alcoholic fermentation. Most processed foods have two or three ingredients, and are recognizable as modified versions of Group 1 foods. They are edible by themselves or, more usually, in combination with other foods.

The purpose of processing here is to increase the durability of Group 1 foods, or to modify or enhance their sensory qualities.

Group 4. Ultra-processed Foods

Ultra-processed foods, such as soft drinks, sweet or savoury packaged snacks, reconstituted meat products and pre-prepared frozen dishes, are not modified foods but formulations made mostly or entirely from substances derived from foods and additives, with little if any intact Group 1 food.

Ingredients of these formulations usually include those also used in processed foods, such as sugars, oils, fats or salt. But ultra-processed products also include other sources of energy and nutrients not normally used in culinary preparations. Some of these are directly extracted from foods, such as casein, lactose, whey and gluten.

Many are derived from further processing of food constituents, such as hydrogenated or interesterified oils, hydrolysed proteins, soya protein isolate, maltodextrin, invert sugar and high-fructose corn syrup.

Additives in ultra-processed foods include some also used in processed foods, such as preservatives, antioxidants and stabilizers. Classes of additives found only in ultra-processed products include those used to imitate or enhance the sensory qualities of foods or to disguise unpalatable aspects of the final product. These additives include dyes and other colours, colour stabilizers; flavours, flavour enhancers, non-sugar sweeteners; and processing aids such as carbonating, firming, bulking and anti-bulking, de-foaming, anti-caking and glazing agents, emulsifiers, sequestrants and humectants.

A multitude of sequences of processes is used to combine the usually many ingredients and to create the final product (hence ‘ultra-processed’). The processes include several with no domestic equivalents, such as hydrogenation and hydrolysation, extrusion and moulding, and pre-processing for frying.

The overall purpose of ultra-processing is to create branded, convenient (durable, ready to consume), attractive (hyper-palatable) and highly profitable (low-cost ingredients) food products designed to displace all other food groups. Ultra-processed food products are usually packaged attractively and marketed intensively.

For example, roasted peanuts fall into Group 1. Add salt to them and they fall into Group 3. Add “sea salt, spices (contains celery), dried onion, dried garlic, paprika, natural flavor, sugar, gelatin, torula yeast, cornstarch, dried corn syrup, maltodextrin” to them, as Planters does, and they fall into Group 4 … making them, by design, difficult to eat just a few.

The Open Food Facts website is a searchable database. It’s still young but has over 800,000 products. Try it! (I just looked up Cheerios and Silk Soymilk: both NOVA Group 4 – to be avoided.)

Food Processing Contributed To Human Evolution

A diorama or model showing Homo erectus, the earliest human species that is known to have controlled fire, from inside the National Museum of Mongolian History in Ulaanbaatar, Mongolia. Source: Wikipedia: Control Of Fire By Early Humans

Richard Wrangham argued in his 2009 book, “Catching Fire: How Cooking Made Us Human” that when our ancestors learned to cook food, it changed how they developed:

Wikipedia, Catching Fire: How Cooking Made Us Human

Humans (species in the genus homo) are the only animals that cook their food and Wrangham argues Homo erectus emerged about two million years ago as a result of this unique trait. Cooking had profound evolutionary effect because it increased food efficiency which allowed human ancestors to spend less time foraging, chewing, and digesting. H. erectus developed a smaller, more efficient digestive tract which freed up energy to enable larger brain growth. Wrangham also argues that cooking and control of fire generally affected species development by providing warmth and helping to fend off predators which helped human ancestors adapt to a ground-based lifestyle. Wrangham points out that humans are highly evolved for eating cooked food and cannot maintain reproductive fitness with raw food.

Cooking is a form of food processing. So is grinding. So is chewing although as we saw with almonds, chewing isn’t as effective as other forms; some of those almonds and their fat and calories get excreted.

Food processing breaks down cell walls and decreases the size of food particles (increasing their surface area), giving digestive juices and enzymes more product to work on. It increases availability of nutrients that would otherwise go right through us. We absorb more, with less effort, and we absorb it faster. This can be a good thing, as Wrangham describes, or it can create problems, as we saw in the rats in my previous post.

Processing food by cooking was clearly an advantage for early humans. What were they cooking? Everything, but starches took center stage, so much so that:

Compared with chimpanzees, humans boast many more copies of the gene that makes salivary amylase — a saliva enzyme that breaks down starch into digestible sugars.” … “High starch foods and a high starch diet have been an important evolutionary force for humans,” says George Perry, an anthropologist at Arizona State University.

Here’s a new study:

Earliest Evidence Of The Cooking And Eating Of Starch, Eurekalert, 17 May 2019

New discoveries made at the Klasies River Cave in South Africa’s southern Cape, where charred food remains from hearths were found, provide the first archaeological evidence that anatomically modern humans were roasting and eating plant starches, such as those from tubers and rhizomes, as early as 120,000 years ago.

The new research by an international team of archaeologists, published in the Journal of Human Evolution, provides archaeological evidence that has previously been lacking to support the hypothesis that the duplication of the starch digestion genes is an adaptive response to an increased starch diet.

“Our results showed that these small ashy hearths were used for cooking food and starchy roots and tubers were clearly part of their diet, from the earliest levels at around 120,000 years ago through to 65,000 years ago,” says Larbey. “Despite changes in hunting strategies and stone tool technologies, they were still cooking roots and tubers.”

Starch diet isn’t something that happens when we started farming, but rather, is as old as humans themselves,” says Larbey. Farming in Africa only started in the last 10 000 years of human existence.

“Evidence from Klasies River, where several human skull fragments and two maxillary fragments dating 120 000 years ago occur, show that humans living in that time period looked like modern humans of today. However, they were somewhat more robust,” says Wurz.

What I’m saying here is that processed foods are a good thing. We evolved to eat them, especially starches. The problem with modern processed foods is that during the course of processing, things are taken away or added. We have created food we didn’t evolve to eat. It’s wrecking havoc with our health. I’ll talk about that in my next post.

Here’s a fantastic video I found of a man who cultivated a yam and cooked it using no modern tools. Something else. Source: Yam, Cultivate and Cook.

Repost: Eating Processed Food Makes It Easier To Gain Weight (Which Was Not A Bad Thing For Our Ancestors)

This is a repost from 2009 and 2012. I was motivated to look it up when I saw a new study about processed food and how it contributes to weight gain. Let me repost this old one and I’ll address the new study and some thoughts about processed food in follow-up posts.


Can just changing the texture of food, processing it, contribute to weight gain?

That was a question Kyoko Oka, et al. asked in:
Food Texture Differences Affect Energy Metabolism In Rats, Journal of Dental Research, June 2003*

Two groups of rats were fed either standard pellets or easily-chewed, soft pellets (made softer by increasing air content, as is done in breakfast cereals).

  • Calorie intake was measured to be the same in both groups.
  • Nutritional composition of diet was the same in both groups.
  • Meal duration was the same in both groups.
  • Calorie expenditure via locomotion was measured to be the same in both groups.

If energy intake, nutrient intake, and energy expenditure (activity) are similar, you would expect body weight and body fat to be similar. That wasn’t the case.


  • After 18 weeks and beyond, “body weight in the soft-fed group was significantly greater.”
  • After 22 weeks the rats were dissected. Weight of abdominal fat in the soft-fed group was significantly greater, enough to designate the rats as obese.
  • The increased body weight in the soft-fed rats was due to increased body fat.

The authors concluded:

“In this study, 22 weeks was long enough to produce obesity in soft-fed rats.”


The cost for digestion in the soft-fed rats was lower. This cost was measured in body temperature, which was significantly lower in the soft-fed group after a meal (up to 1 hour). Body temperature (thus, energy expenditure) was also significantly lower in the soft-fed group “during the dark period” or overnight.

If weight loss and reduction of body fat are the goal, merely reducing the number of calories consumed won’t be as effective as also reducing the amount of processed food consumed.

* I read about this study in Richard Wrangham’s book “Catching Fire: How Cooking Made Us Human” back in 2009.

A Song For You


“A Song for You” is a song written and originally recorded by rock singer and pianist Leon Russell for his first solo album Leon Russell, which was released in 1970 on Shelter Records. A slow, pained plea for forgiveness and understanding from an estranged lover, the tune is one of Russell’s best-known compositions. Russell not only sings and plays piano on the recording, but also plays the tenor horn that is accompanying. It has been performed and recorded by over 200 artists, spanning many musical genres. Elton John has called the song an American classic.

On January 17, 2018, “A Song For You” was added to Grammy Hall of Fame.

Leon Russell singing his “A Song for You” in 1970:

Donny Hathaway singing “A Song for You” in 1971:

Ray Charles singing “A Song for You.” It earned him the 1994 Grammy Award for Best Male R&B Vocal Performance.

You Can Change Your Brain

This is interesting …

The brain you had, and have, does not necessarily have to be the brain you have going forward.
The thoughts and beliefs and behaviors you had, and have, do not necessarily have to be the thoughts and beliefs and behaviors you have going forward.

How You Can Re-Programme Your Brain, BBC Radio 4.

For years, neuroscientists presumed that the structure of the adult brain was fixed. We were stuck with what we’d got.

But by the 1960s experimental evidence started to emerge suggesting the contrary: that in fact parts of the brain might be plastic, meaning they are able to adapt, grow and even regenerate.

What London cab drivers revealed about our brains:

Hop in the back of a London black cab, offer up your destination, and the driver is duty-bound to take you there by the fastest possible route. In order to do this, the cab driver has to memorise all the roads in London. No mean feat. Mastering “The Knowledge” normally takes two to four years.

Neuroscientists studying cabbies discovered that while this giant act of memorisation was undertaken, significant changes occurred in a region of the driver’s brain called the hippocampus. They found, using new neuroimaging technology, that it actually got bigger.

This had huge implications. It suggested that the brain we have is not the brain we are fated to have forever, and that we have the ability to make changes.

How do you change your brain? By changing your thoughts:

Experiments have proven that the brain retains the capacity for large-scale change – in structure and function – well into our 60s, 70s, and 80s. One of the most important of these changes is the growth of new neurons, known as neurogenesis.

Cognitive Behavioural Therapy, or CBT, is a talking therapy that can help you manage your problems by changing the way you think and behave. When we are taught to think about our life experiences differently, during this kind of psychological intervention, it can actually act back on the structure and function of the brain.

What gets me about this is that you can actually change the structure of your brain. And it’s not hard to do.

Every time you learn something new or have a new thought, new connections in the mind and new physical structures in the brain are formed and consolidated.

Study: High-Fat Diet Decreases Insulin Sensitivity

A diet high in fat, especially saturated fat, has been shown to increase lipids inside muscle cells and decrease insulin sensitivity. Photo credit: Cristian Baitg Schreiweis/iStockphoto

This is an older study but it shows this was known for decades: a high-fat diet contributes to insulin resistance, a hallmark of type 2 diabetes:

Effects Of Intravenous And Dietary Lipid Challenge On Intramyocellular Lipid Content And The Relation With Insulin Sensitivity In Humans, Diabetes, November 2001

In just three days on a high-fat diet, 12 young, healthy, male, normal-weight, nondiabetic volunteers, showed substantially increased lipid levels inside their muscle cells and a decrease in insulin sensitivity, similar to what occurred after an overnight intravenous lipid infusion.

– In the diet protocol, 12 male subjects ingested both a high-fat and low-fat diet for 3 days each.
– After the high-fat diet, IMCL [IMCL is intramyocellular lipid, that is, lipid located within muscle cells] levels increased significantly. Insulin sensitivity decreased to 83.3 ± 5.6% of baseline (P = 0.033).
– There were no significant changes in insulin sensitivity or IMCL levels after the low-fat diet.

Each subject received a high-fat low-carbohydrate diet and a low-fat high-carbohydrate diet for 3 consecutive days each.

1) High-fat diet: fat: 55–60% of energy intake, carb: 30–35%, protein: 11–16%
2) Low-fat diet: fat: 18–23%, carb: 62–64%, protein: 16–18% protein

After ingestion of the high-fat diet for 3 days, both IMCL levels and insulin sensitivity were clearly affected.

This conclusion agrees with findings from several studies that have showed that a fat-rich diet can increase plasma NEFA [nonesterified fatty acid] levels, and, moreover, that this increase in NEFA levels is accompanied by a decrease in insulin sensitivity (3,10,11,24,25).

In Tsimane Culture, Social Status Grows With Age

In a long-term study of the Tsimane, researchers find productivity and social status peak long after physical strength. Photo credit: Paul Hooper

Aging Gracefully In The Rainforest, Eurekalert, May 2017


The Tsimane of Bolivian Amazonia aren’t so different from the people living around you. Most adults live to 70, a few even to 90. They start aging in their 30s, just like the rest of us. And for the Tsimane, the onset of physical aging isn’t really tantamount to decline. Between the ages of 40 and 60, many individuals reach a social and economic peak when hard work and life experience bear their fruit.

In an article that appears in the current issue of Evolutionary Anthropology, researchers synthesize over 15 years of theoretical and empirical findings from long-term study of the Tsimane forager-farmers. This project — the Tsimane Health and Life History Project — sought to understand the human life course outside the context of industrial civilization. It followed a number of complex variables, from biomarkers related to health and aging, to surveys of social status, to observations of economic productivity.

“This project is really an example of big data outside the narrow industrialized context,” explains co-author Paul Hooper, an anthropologist based at the Santa Fe Institute. “The story the Tsimane bear out, through a mountain of data, is the story of all humanity. It’s the ability of a human to produce resources and support the people that they care about later in life, in the 40s, 50s, and 60s.”

Hooper credits adaptation, experience, and maturation for bringing about these late-life benefits. Although their physical strength peaks in their 20s, Tsimane men in middle and older age adapt by devoting less time to hunting and more to horticulture. Tsimane women divide their time between horticulture, food processing, and childcare. While less physically demanding than hunting, horticulture is productive enough that Tsimane between 40 and 70 wind up producing the majority of calories for their extended families. And, because members of older generations are identified as being the best storytellers and advisors, their social stock also rises with age.

“We were able to see that as adults age and their bodies become weaker, instead of ceasing to be productive, folks adaptively shift their behavior into arenas where their aging bodies perform quite well,” Hooper explains.

From an evolutionary standpoint, the findings suggest that human fitness cannot be measured outside of complex social and intergenerational contexts; that our relatively long human lifespans may have evolved to maximize not only individual survival, but also the survival of children and grandchildren. Aging, then, can be understood as a passing of resources and wisdom to the next generation.

The reality of aging, particularly for humans, is that there’s a potential for really high performance and quality of life remarkably late into the aging process.”

This struck me: “human fitness cannot be measured outside of complex social and intergenerational contexts.” The anti-aging movement, the life-extension movement, these are being pursued with an individual focus. They are asking, “How can a human being, an individual, separate and distinct from the beings around it, live a longer and healthier life?” But this study of the Tsimane show that we are not so separate from our surroundings, from the people around us.

When people are respected and valued and nurtured, they thrive. Their health and longevity reflect that care. Is the reverse true? When people are marginalized, do they suffer poorer health?

The Lancet Public Health: Ageism Linked To Poorer Health In Older People In England, Eurekalert, 3 April 2019

They describe health effects linked to age discrimination and speculate on reasons:

Exposure to age discrimination can provoke stress responses harmful to both mental wellbeing and physical health.

People may use unhealthy behaviours, like smoking, drinking, poor diet or physical inactivity [I’ll add here use of prescription or illicit drugs], to cope with experiences of age discrimination.

Age discrimination in healthcare could mean that older patients are not receiving the same standard of care as their younger counterparts.

People can internalize discrimination. They come to see themselves, even subconsciously, through a filter of how society sees them. I think this is at the root of people trying to look, think, and act younger. Youth is valued in our society, age not as much.

There’s a lot we can learn from the Tsimane.

Jose, a member of the Tsimane group who is 75 years old, stands in the plantain field he planted in Bolivia’s Amazon rain forest. Photo: Matthieu Paley/National Geographic. Source: NPR: Who Has The Healthiest Hearts In The World?