When I did the research for the TV series “Why are we fat?” presented by New Zealand Chef (and programme guinea pig) Simon Gault, the overwhelming reason experts around the world gave for the massive increase in our collective weight was the amount of ultra-processed food we now eat. In America the average diet is made up of around 60% ultra processed foods. These foods typically have high percentages of three primary ingredients: refined starch, sugar and refined seed oils.
Despite this connection – up until now – there has not been a randomised controlled diet study comparing a diet high in ultra-processed foods against a diet with unprocessed foods, and each diet’s effect on food intake and weight.
Dr Kevin Hall, a nutrition scientist has recently completed a study which shows that eating ultra-processed foods contributes to weight gain.
What is the definition of ultra-processed and unprocessed foods?
Ultra-processed foods:
“Ultra-processed foods are industrial food and drink formulations made mostly or entirely from substances derived from foods, together with additives. The ingredients, the various processing techniques and the sequences of stages used for the manufacture of ultraprocessed foods (hence ‘ultra-processed’) are designed to create durable, accessible, convenient, hyper-palatable, highly profitable ready-to-eat, ready-to-drink or ready-to-heat products liable to displace all other NOVA food groups – natural or minimally processed foods, processed culinary ingredients and processed foods – and the dishes and meals made with them. Examples of typical ultra-processed foods are soft drinks; sweet or savoury packaged snacks; confectionery, mass-produced packaged breads, buns, biscuits and cakes; hot dogs, poultry and fish ‘nuggets’ and other reconstituted meat products; ‘instant’ soups and noodles; industrialized desserts; and industrially pre-prepared pizzas, pies and other dishes and meals.” (reference)
Unprocessed or minimally processed foods:
“Group 1: Unprocessed or minimally processed foods, such as fresh, dry or frozen fruits and vegetables; packaged grains and pulses; grits, flakes or flours made from corn, wheat, rye; pasta, fresh or dry, made from flours and water; eggs; fresh or frozen meat and fish; fresh or pasteurized milk.” (reference)
How the study was carried out
Participants: 10 male and 10 females with stable weight.
The setting of study: The participants stayed in the Metabolic Clinical Research Unit (MCRU) for a continuous 28 day period.
Study structure: Subjects were randomly assigned to either the ultra-processed diet, or the unprocessed diet for 2 weeks, then immediately swapped to the other diet for the second 2 weeks.
Food: The diet food was prepared for the participants. Meals were matched for total calories, energy density, macronutrients, fiber, sugar, and sodium, but widely differed in the percentage of calories derived from ultra-processed versus unprocessed foods as defined according to the NOVA classification scheme (Monteiro et al., 2018). Snacks and water were freely available. The meals had twice the number of calories each participant needed to maintain their current weight. The reason for this was to allow each person to eat freely (ad libitum) in order to satisfy their appetitite.
The participants were allowed 60 minutes to eat a meal, and all food not eaten was removed and weighed. The length of time they spent eating was timed.
Here are examples of the different meals, there were 7 days of meals on rotation for the two weeks on each diet.
Assessments of satiety
All participants answered questions on hunger and fullness, on a scale of 0 to 100 (“not at all” to “extremely”), before a meal, and 30 – 60 minutes after meals for 2 to 3 hours.
Results
Differences in caloric intake:
Daily energy intake was 508±106 kcal/d greater during the ultra-processed diet (p=0.0001). Neither the order of the diet assignment (p=0.64) nor sex (p=0.28) had significant effects on the energy intake differences between the diets.
Specific increases in food: At breakfast and lunch, when the ultraprocessed diet was consumed – both carbohydrates and fats increased significantly. Protein intake was significantly lower at lunch when ultraprocessed food was eaten. Protein has an effect on hormones promoting satiety so this may be a factor in reduced calories also.
Why did the participants eat more food when they were given ultraprocessed meals?
Did the food taste better? No – none of the participants reported any difference in pleasantness.
The speed of eating: One interesting observation is that the meal eating rate was greater in terms of calories consumed per minute, and grams per minute – that is more calories were consumed in a shorter space of time when eating ultraprocessed food. This is a likely result of the refined nature of ultraprocessed food, making it easier to chew and swallow quickly.
Body weight changes: Participants gained 800 grams on average during the ultraprocessed 2 weeks, and lost 1.1kg on average during the umprocessed diet phase.
Hormones that control appetite: The appetite suppressing hormone PYY increased during the unprocessed food diet compared to baseline and the ultraprocessed food diet. The hunger hormone grehlin was decreased in the unprocessed food diet.
Other measures:
A number of other measures were taken, continous glucose monitoring, lipids, energy expenditure, insulin sensitivity and others which you can see in the study, and changes between groups were not significant.
Blood glucose and insulin
Interestingly continuous glucose and insulin monitoring showed no difference between the groups, despite this, when eating unprocessed food participants lost weight.
THere is no such entity as “calories.” They are entirely fictitious. Mega-cycles, claories, inverse fermions ALL fictitious INVENTIONS and ALL the SAME- None of them are intrisnic to food. Yu could use calories for nuclear explosions….
Energy is nt itself ANYTHING. Energy is not ANY kind of stuff, thing or rnity. it is just a NUMBER, a human INVENTED FICTION. Inverse fermions, joules calories-NONE of those exist. People east ATOMS- MATTER- STUFF. Matter and energy are NOT at all related. Energy is fictitious and CANNOT act on human bodies. NOBODY eat calories……Natural food simply has more WATER in it ( hydrogen and oxygen atoms) atoms and less carbon – The hydrogen and oxygen ATOMS are easily removed and excreted. Carbon is difficult to remove and excrete
Stop spreading misinformation , you quack. Those with certain gene defects WILL become severely obese IRRESPECTIVE of food intake.Obesity is NOT about overeating- many normal and lean people overeat. Overeating is not SUFFICIENT t cause obesity…How fat cells become dysregulated is central to obesity as is partitioning and handling of ingested food and gene defects.
I’ve had to adjust my diet and exercise, however now – at 8 years post menopuase, I feel great. I do recommend women look at HRT, bioidentical in particular if having ongoing hot flushes and other issues. I strength train, powerlifting and highly recommend post menopausal women do this – both for increasing insulin sensitivity and building a good amount of muscle mass and keeping bones strong. I eat higher protein, fruit and veg carbs and minimal added fat. This is what currently works for me. Added supplements include a good quality multivitamin and mineral, extra zinc and magnesium (great for sleep) Taurine, ubiquinol, vitamin C, omega 3. I also use collagen powder – great for joints and skin. I still fit into all my pre menopause clothes.