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Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake.
Hall, KD, Ayuketah, A, Brychta, R, Cai, H, Cassimatis, T, Chen, KY, Chung, ST, Costa, E, Courville, A, Darcey, V, et al
Cell metabolism. 2019;30(1):67-77.e3
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Diets high in ultra-processed foods have been related to several poor health outcomes and even death, possibly due to properties that make them highly palatable resulting in overeating and obesity. However, to date, there are few studies that demonstrate this relationship. This randomised control trial of 20 individuals aimed to compare the effects of an ultra-processed diet to an unprocessed diet on energy intake. The results showed that the ultra-processed diet resulted in higher energy intakes due to increased carbohydrates and fat, whereas energy intake during the unprocessed diet remained stable and this was not due to differences in pleasantness of familiarity. During the ultra-processed diet participants gained weight, and lost weight during the unprocessed phase, due to increased energy intake. It was concluded that eliminating ultra-processed foods from the diet decreases energy intake resulting in weight loss. Healthcare professionals could use this study to understand the importance of recommending a diet without ultra-processed foods to decrease overeating and improve health.
Abstract
We investigated whether ultra-processed foods affect energy intake in 20 weight-stable adults, aged (mean ± SE) 31.2 ± 1.6 years and BMI = 27 ± 1.5 kg/m2. Subjects were admitted to the NIH Clinical Center and randomized to receive either ultra-processed or unprocessed diets for 2 weeks immediately followed by the alternate diet for 2 weeks. Meals were designed to be matched for presented calories, energy density, macronutrients, sugar, sodium, and fiber. Subjects were instructed to consume as much or as little as desired. Energy intake was greater during the ultra-processed diet (508 ± 106 kcal/day; p = 0.0001), with increased consumption of carbohydrate (280 ± 54 kcal/day; p < 0.0001) and fat (230 ± 53 kcal/day; p = 0.0004), but not protein (-2 ± 12 kcal/day; p = 0.85). Weight changes were highly correlated with energy intake (r = 0.8, p < 0.0001), with participants gaining 0.9 ± 0.3 kg (p = 0.009) during the ultra-processed diet and losing 0.9 ± 0.3 kg (p = 0.007) during the unprocessed diet. Limiting consumption of ultra-processed foods may be an effective strategy for obesity prevention and treatment.
2.
Fast food fever: reviewing the impacts of the Western diet on immunity.
Myles, IA
Nutrition journal. 2014;13:61
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This 2014 review delves into the impact that an over-indulgence in foods high in sugar, salt, saturated fats, genetically modified foods, gluten and artificial sweeteners may have on our immune system. The modern western diet is generally characterised as being abundant in these nutrient-poor foods, which exert an unhealthful impact on the body. They report that sugars increase inflammatory markers and reduce white blood cell production. Artificial sweeteners appear to be less inflammatory however data is limited. There is some suggestion that saccharin and sucralose interfere with digestive enzymes and are implicated in Inflammatory Bowel Disease. High salt may increase inflammatory cytokines. Saturated fats and high omega 6 fatty acids from vegetable oils increase inflammatory immune markers such as C-Reactive protein. Omega 3 polyunsaturated fats are generally associated with anti-inflammatory effects and regulating immune mediators. Gluten inappropriately activates an immune T-cell response. GM foods may have protective effects against malnutrition but have been shown to induce an allergic response in some cases. There is also concern that genetic modifications can be internalised by our gut bacteria and passed on to offspring. The review concludes that poor dietary choices are encoded into our gut and increase inflammation, and thus reduce our immune resilience to control infection.
Abstract
While numerous changes in human lifestyle constitute modern life, our diet has been gaining attention as a potential contributor to the increase in immune-mediated diseases. The Western diet is characterized by an over consumption and reduced variety of refined sugars, salt, and saturated fat. Herein our objective is to detail the mechanisms for the Western diet's impact on immune function. The manuscript reviews the impacts and mechanisms of harm for our over-indulgence in sugar, salt, and fat, as well as the data outlining the impacts of artificial sweeteners, gluten, and genetically modified foods; attention is given to revealing where the literature on the immune impacts of macronutrients is limited to either animal or in vitro models versus where human trials exist. Detailed attention is given to the dietary impact on the gut microbiome and the mechanisms by which our poor dietary choices are encoded into our gut, our genes, and are passed to our offspring. While today's modern diet may provide beneficial protection from micro- and macronutrient deficiencies, our over abundance of calories and the macronutrients that compose our diet may all lead to increased inflammation, reduced control of infection, increased rates of cancer, and increased risk for allergic and auto-inflammatory disease.