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FACTORS INFLUENCING WEIGHT GAIN AFTER GASTRIC BYPASS

  1. Top of page
  2. FACTORS INFLUENCING WEIGHT GAIN AFTER GASTRIC BYPASS
  3. INTAKE OF POLYPHENOLS DURING MIDLIFE AFFECT COGNITIVE FUNCTION
  4. COMPENSATORY MECHANISMS ENSURE ADEQUATE PROTEIN STATUS

Freire RH, Borges MC, Alvarez-Leite JI, and Correia MI. Food quality, physical activity, and nutritional follow-up as determinant of weight regain after Roux-en-Y gastric bypass. Nutrition. 2012;28:53–58.

Bariatric surgery is considered one of the most effective means of treating severe obesity. Successful patients lose at least 50% of initial excess weight, and frequently see marked improvements in hypertension, diabetes, and quality of life. However, weight regain is a serious concern, with approximately half of patients gaining weight 2 years post-surgery, with a concomitant return of comorbid illness and decrease in quality of life. Friere et al. examined a number of lifestyle factors in Roux-en-Y gastric bypass patients to identify those factors which would be predictive of success or failure in this patient population.

One hundred patients who underwent gastric bypass surgery between 1998 and 2008 were enrolled in the study. Participants were categorized into three groups according to postsurgical time: group 1: up to 24 mo; group 2: 25–60 mo; group 3: over 61 mo. Participants completed questionnaires assessing nutritional intake and dietary habits, weight loss, change in comorbid conditions, participation in postsurgical nutritional follow-up visits, and physical activity. Percentage of early weight loss (EWL), defined as weight lost during the first 18–24 mo post-surgery, was calculated using current body weight and starting body weight. As weight regain is commonly seen following the second year, weight regain was separated into three categories: 2–5% regain, 5.1–10% regain, and over 10.1% regain. The average body mass index (BMI) at the time of surgery was 54.9 kg/m2. After surgery, BMIs varied with progressive reductions observed over the first 2 years, followed by gradual increases after 5 years. Average EWL was 59.1%, with 69% of patients meeting the successful outcome criteria of 50% EWL. EWL was not affected by quality of diet, physical exercise, or socioeconomic status. Over time, 56% of patients had regained weight, with 29% of patients regaining over 10.1%. Poor diet quality, excessive intake of energy, and intake of snacks, sweet foods, and oils/fatty foods were associated with weight regain. Only 20% of participants reported engaging in regular physical activity before surgery. After surgery, 55% of participants engaged in regular physical activity. Although activity was not associated with EWL, exercise was associated with lower weight regain. Attendance at postsurgical nutritional follow-up declined the further out in time participants were from surgery, and lack of nutritional counseling was also associated with weight regain.

The results of this study indicate that long-term maintenance of weight loss is challenging, even for individuals who have undergone gastric bypass surgery, and significant weight regain is not uncommon. While EWL is significant following surgery and may be independent of nutritional support or physical activity, long-term successful weight loss likely requires a multifaceted approach that includes regular exercise, ongoing support from nutritional counselors, and vigilance regarding both the quantity and quality of the diet.

INTAKE OF POLYPHENOLS DURING MIDLIFE AFFECT COGNITIVE FUNCTION

  1. Top of page
  2. FACTORS INFLUENCING WEIGHT GAIN AFTER GASTRIC BYPASS
  3. INTAKE OF POLYPHENOLS DURING MIDLIFE AFFECT COGNITIVE FUNCTION
  4. COMPENSATORY MECHANISMS ENSURE ADEQUATE PROTEIN STATUS

Kesse-Guyot E, Fezeu L, Andreeva VA, Touvier M, Scalbert A, Hercberg S, and Galan P. Total and specific polyphenol intakes in midlife are associated with cognitive function measured 13 years later. J Nutr. 2012;142:76–83.

Polyphenols are abundant in plant foods and have been targeted as a promising, nutritionally modifiable factor for protecting against the cognitive decline seen frequently with aging. A number of studies show that polyphenols, particularly flavonoids, may have neuroprotective effects, can increase neurogenesis, and may prevent age-related damage in the central nervous system, perhaps through antioxidant or anti-inflammatory actions. In a recently published article, Kesse-Guyot et al. argue that many of these findings do not take into account the specific physiological properties or bioavailability of specific phenolic compounds, and that more precise examination of these dietary variables and cognitive outcome are needed. In their report, the authors employ the new Phenol-Explorer database, which provides data on 502 different polyphenols, in estimating polyphenol intake in the Supplementation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort.

The SU.VI.MAX trial (1991–2002) was originally designed to test the potential efficacy of daily supplementation with antioxidant vitamins and minerals in protecting against cancer, cardiovascular disease, and all-cause mortality. SU.VI.MAX 2 (2007–2009) extended the original trial and included a focus on the quality of aging. Men (aged 45–60 years) and women (aged 35–60 years) were enrolled into SU.VI.MAX with a planned original follow up of 8 years (N=12, 741). A total of 6,850 participants continued into SU.VI.MAX 2, and of those participants, a total of 2,574 with complete cognitive tests and complete dietary records were included in the present analysis. Food intakes were assessed using 24-h dietary records collected every 2 months (six records/year). Cognitive assessments were collected 13 years after enrollment and neuropsychological testing included measurements of memory, mental flexibility, semantic fluency, attention, and other aspects of global cognitive function. Among the participants, the main dietary sources of polyphenols were coffee, fruits, wine, and tea. The two main classes of polyphenols consumed were flavonoids, including anthocyanins, theaflavins, flavones, and dihydroflavonols, and hydroxycinnamic acids. Total high polyphenol intake was associated with better language and verbal memory, and high intakes, particularly of catechins, theaflavins, flavonols, and hydroxybenzoic acids, conferred the greatest benefits. In contrast, executive functioning did not benefit from high intake of polyphenols, and a negative association was seen between intakes of dihydrochalcones, catechins, proanthocyanidins, and flavonols, and executive functioning.

The authors indicate there are, at present, no proposed mechanisms that would account for the negative impact of polyphenols on executive function. However, other research shows that some nutrients can have different, region-specific effects that could account for the present observations. Additionally, the authors acknowledge that their analysis included a large number of variables, and further study in this area is needed to confirm the present findings. As the global population ages, preservation of cognitive function becomes a pressing issue. In the current study, intake of several phenolic compounds was associated with preserved verbal memory and language processing – two areas of cognitive functioning that are particularly vulnerable to dementia.

COMPENSATORY MECHANISMS ENSURE ADEQUATE PROTEIN STATUS

  1. Top of page
  2. FACTORS INFLUENCING WEIGHT GAIN AFTER GASTRIC BYPASS
  3. INTAKE OF POLYPHENOLS DURING MIDLIFE AFFECT COGNITIVE FUNCTION
  4. COMPENSATORY MECHANISMS ENSURE ADEQUATE PROTEIN STATUS

Griffioen-Roose S, Mars M, Siebelink E, Finlayson G, Tomé D, and de Graaf C. Protein status elicits compensatory changes in food intake and food preferences. Am J Clin Nutr. 2012;95:32–38.

Protein is an essential dietary requirement that provides both nitrogen and amino acids, which are necessary to maintain life. In humans, protein requirements range between 10 and 25% of total daily energy intake, or about 40–100 g/day. Some research shows that food-restricted participants selectively prefer higher protein foods, but it is unclear whether specific behavioral strategies are used to maintain adequate protein intake. Griffioen-Roose et al. proposed that individuals who were maintained on low-protein diets for a number of days would shift their dietary preferences to higher-protein foods to offset decrements in protein intake.

Thirty-seven participants (25 women) were randomized into one of two treatment conditions: 14-day low-protein diet (0.5 g/kg body weight/day) or 14-day high-protein diet (2.0 g/kg body weight/day). After 14 days on their respective diets, participants underwent a 2.5-day observational period of ad libitum food intake. Participants subsequently underwent a 2-week washout phase and were then given the other type of diet according to a crossover design. After the next 14 days, participants again underwent a 2.5-day observational period of ad libitum food intake. Food was provided to the participants by the researchers, and during the ad libitum phase, meal packages providing more than double the estimated daily energy requirements were provided to allow participants to choose freely among the different types of foods. Food intake was measured by weighing the remainder of foods that were not consumed by the participant. Behavioral measures included ratings of hunger and appetite, and ratings for food preference and palatability. Participants reported being more hungry, having greater desire to eat, and increased desire to eat something savory during the low-protein phase of the diet relative to the high-protein phase. Following the low-protein diet, total protein intake during the ad libitum phase was 13% higher relative to the ad libitum phase following the high-protein diet. Total energy intake during the ad libitum phase did not differ between the two diet conditions.

The data from this study show a specific increase in protein intake following a 14-day low-protein diet that is independent of total energy intake. Additionally, preferences for savory, high-protein foods were increased when a low-protein diet was followed relative to a high-protein diet. The authors suggest these data support the notion that both food intake and food preferences change in response to protein deficit.