Maternal effects are long‐lasting and influence female offspring's reproductive strategy in the swordtail fish Xiphophorus multilineatus

The adaptive benefits of maternal investment into individual offspring (inherited environmental effects) will be shaped by selection on mothers as well as their offspring, often across variable environments. We examined how a mother's nutritional environment interacted with her offspring's nutritional and social environment in Xiphophorus multilineatus, a live‐bearing fish. Fry from mothers reared on two different nutritional diets (HQ = high quality and LQ = low quality) were all reared on a LQ diet in addition to being split between two social treatments: exposed to a large adult male during development and not exposed. Mothers raised on a HQ diet produce offspring that were not only initially larger (at 14 days of age), but grew faster, and were larger at sexual maturity. Male offspring from mothers raised on both diets responded to the exposure to courter males by growing faster; however, the response of their sisters varied with mother's diet; females from HQ diet mothers reduced growth if exposed to a courter male, whereas females from LQ diet mothers increased growth. Therefore, we detected variation in maternal investment depending on female size and diet, and the effects of this variation on offspring were long‐lasting and sex specific. Our results support the maternal stress hypothesis, with selection on mothers to reduce investment in low‐quality environments. In addition, the interaction we detected between the mother's nutritional environment and the female offspring's social environment suggests that female offspring adopted different reproductive strategies depending on maternal investment.     

Effects of Doubling the Portion Size of Fruit and Vegetable Side Dishes on Children's Intake at a Meal

Increasing the portion size of energy‐dense entrées has been shown to increase children's energy intake during a meal. It remains to be investigated whether serving larger portions to children can be used to promote intake of more healthful foods, such as fruits and vegetables (F&V). The aim of the present study was to examine the effects of increasing the portion size of F&V side dishes on children's intake. Forty‐three children (22 boys, 21 girls), aged 5–6 years, were served dinner once a week for 2 weeks. Each dinner consisted of pasta with tomato sauce, three F&V side dishes (broccoli, carrots, and applesauce), and milk. The portion size of the F&V was doubled between experimental conditions whereas the size of the pasta remained constant. Doubling the portion size of the side dishes resulted in a 43% increase in children's intake of the fruit side dish (P = 0.001), but did not affect children's intake of the two vegetable side dishes (P > 0.60). Further, when the portion size of F&V side dishes was doubled, children ate significantly less of the pasta (P = 0.04). The difference in meal energy intake between portion size conditions (19.5 ± 16.3 kcal) was not significant (P = 0.24). Although more studies are needed to understand whether increases in portion size can influence vegetable intake, children did eat more in response to a large quantity of a preferred low energy‐dense fruit side dish at meals. Thus variations in portion size can be used strategically to help children achieve the recommended intake of fruits.     

Associations of Maternal Diabetes During Pregnancy with Overweight in Offspring: Results from the Prospective TEDDY Study

Objective: This study aimed to determine the relationship between different forms of, and potential pathways between, maternal diabetes and childhood obesity at different ages. Methods: Prospective cohort data from The Environmental Determinants of Diabetes in the Young (TEDDY) study, which was composed of 5,324 children examined from 0.25 to 6 years of age, were analyzed. Cross‐sectional and longitudinal analyses taking into account potential confounders and effect modifiers such as maternal prepregnancy BMI and birth weight z scores were performed. Results: Offspring of mothers with gestational diabetes mellitus (GDM) or type 1 diabetes mellitus (T1DM) showed a higher BMI standard deviation score and increased risk for overweight and obesity at 5.5 years of age than offspring of mothers without diabetes. While these associations could be substantially explained by maternal prepregnancy BMI in offspring of mothers with GDM, significant associations disappeared after adjustment for birth weight z scores in offspring of T1DM mothers. Furthermore, overweight risk became stronger with increasing age in offspring of mothers with diabetes compared with offspring of mothers without diabetes. Conclusions: Maternal diabetes is associated with increased risk of offspring overweight, and the association appears to get stronger as children grow older. Indeed, intrauterine exposure to maternal T1DM may predispose children to later obesity through increased birth weight, while maternal BMI is more important in children exposed to GDM.     

Effects of acute and chronic protein intake on metabolism, appetite, and ghrelin during weight loss

Objective: This study evaluated the effects of acute and chronic consumption of higher dietary protein on energy expenditure, macronutrient use, appetite, and appetite‐regulating hormones during weight loss in women. Research Methods and Procedures: Thirty‐eight women chronically consuming a 750 kcal/d energy‐deficit diet with a protein content of 30% (higher protein‐chronic diet, HP‐CD, n = 21) or 18% (normal protein‐chronic diet, NP‐CD, n = 17) for 9 weeks were tested. On separate days, metabolic, appetite, and hormonal responses were measured over 4 hours when the women consumed a higher protein‐acute meal (HP‐AM) (30% of energy as protein) or a normal protein‐acute meal (NP‐AM) (18% of energy as protein). Results: With chronic diet groups combined, HP‐AM led to lower respiratory exchange ratio (0.829 ± 0.005 vs. 0.843 ± 0.008; p < 0.05), lower carbohydrate oxidation (p < 0.05), and higher fat oxidation (p < 0.05) compared with NP‐AM. HP‐AM also led to reduced self‐reported postprandial hunger (p < 0.001) and desire to eat (p < 0.001) and lower postprandial ghrelin (252 ± 16 vs. 274 ± 18 ng/mL · 240 minutes, p < 0.05) compared with NP‐AM. No differences in postprandial energy expenditure (PPEE) occurred between meals. When combining acute meals, respiratory exchange ratio was lower (p < 0.05) and protein oxidation (p < 0.001) was higher in the HP‐CD vs. NP‐CD. An acute meal‐by‐chronic diet interaction was observed with PPEE such that HP‐AM led to greater PPEE in the HP‐CD vs. NP‐CD (28.7 ± 2.7 vs. 19.9 ± 2.7 kcal/min for 195 minutes; p < 0.05). Conclusions: During weight loss, thermogenesis and protein use appear to be influenced by chronic protein intake, while appetite and ghrelin are more responsive to acute protein intake.     

Post‐Exercise Substrate Utilization after a High Glucose vs. High Fructose Meal During Negative Energy Balance in the Obese

Objective: To assess the effects of negative energy balance on the metabolic response of a meal containing either glucose or fructose as the primary source of carbohydrate after exercise in obese individuals in energy balance, or negative energy balance. Research Methods and Procedures: Fourteen adults with mean body mass index (BMI) 30.3 ± 1 kg/m², age 26 ± 2 years, and weight 93.5 ± 5.4 kg, adhered to an energy‐balanced (EB) or a negative energy‐balanced (NEB) diet for 6 days. On Day 7, subjects exercised at 70% VO_2peak for 40 minutes then consumed either high glucose (50 g of glucose, HG) or high fructose (50 g of fructose, HF) liquid meal. Substrate utilization was measured by indirect calorimetry for 3 hours. Blood samples were collected before exercise and 0, 30, 60, 120, and 180 minutes after consuming the meal. Results: The HG produced 15.9% greater glycemic (p < 0.05) and 30.9% larger insulinemic (p < 0.05) responses than the HF under both EB and NEB conditions. After the NEB diet, carbohydrate and fat oxidation did not differ for HG and HF. In contrast, carbohydrate oxidation increased 31%, and fat oxidation decreased 39% with HF compared with HG after the EB diet. Thus, HF and HG consumed after exercise produced marked differences in macronutrient oxidation when obese subjects followed an EB diet, but no difference when adhering to a NEB diet. Discussion: The data suggest that the use of fructose in supplements/meals may provide no additional benefit in terms of substrate utilization during a weight loss program involving diet and exercise.     

Effects of age on children's intake of large and self-selected food portions

Objective: Whether developmental periods exist in which children become particularly sensitive to environmental influences on eating is unclear. This research evaluated the effects of age on intake of large and self‐selected portions among children 2 to 9 years of age. Research Methods and Procedures: Seventy‐five non‐Hispanic white children 2 to 3, 5 to 6, and 8 to 9 years of age were seen at a dinner meal in reference, large, and self‐selected portion size conditions in which the size of an entrée was age‐appropriate, doubled, and determined by the child, respectively. Weighed food intake data were collected. Entrée bite size and bite frequency were assessed. Height and weight measurements were obtained. Results: The effect of age on children's intake of the large portion was not significant. Entrée consumption was 29% greater (p < 0.001) and meal energy intake was 13% greater (p < 0.01) in the large portion condition than in the reference condition. Increases in entrée consumption were attributable to increases in average bite size (p < 0.001). Neither child weight nor maternal weight predicted children's intake of large portions. Self‐selection resulted in decreased entrée (p < 0.05) and meal energy (p < 0.01) only among those children who ate more when served the large portion. Discussion: The results of this research confirm that serving large entrée portions promotes increased intake at meals among 2‐ to 9‐year‐old children. These findings suggest that any age‐related differences in children's response to large portions are likely to be smaller than previously suspected.     

Effects of leptin supplementation to lactating Brandt’s voles (<Emphasis Type="Italic">Lasiopodomys</Emphasis><Emphasis Type="Italic">brandtii</Emphasis>) on the developmental responses of their offspring to a high-fat diet

Maternal serum leptin concentrations have been suggested as a key factor in programming growth patterns and protecting against adult metabolic disease in human offspring. However, the role of maternal leptin in the development of wild rodent offspring is not clear. We tested the hypothesis that maternal hyperleptinemia in lactating Brandt’s voles (Lasiopodomys brandtii) can protect their offspring from the risks of high-fat-diet-induced-obesity and insulin resistance. Lactating voles were supplemented with murine leptin (0.64 μg g⁻¹ day⁻¹) or phosphate-buffered saline (control) on days10–17 of lactation (peak lactation). At 12 weeks of age, the female and male offspring of the two maternal groups were randomly assigned to two groups each and fed either a high-fat diet (41% of gross energy as fat) or a control diet (14% of gross energy as fat) until the age of 23 weeks. Body mass, food intake, glucose tolerance and resting metabolic rate were determined in the four offspring groups. After animals were sacrificed, organ masses and adipose tissue distribution, and serum leptin and insulin concentrations were measured. Offspring of leptin-treated mothers showed no significant differences in body mass, energy intake or energy expenditure, body composition, glucose tolerance or serum leptin and insulin concentrations from offspring of control mothers. The high-fat diet induced increases in body mass (by 23% in female and 17% in male offspring) and reduced glucose tolerance in both female and male offspring, indicative of the emergence of insulin resistance, even though digestible energy intake of the male offspring decreased on the high-fat diet. These results indicate that maternal hyperleptinemia during peak lactation in Brandt’s voles did not protect against diet-induced obesity or glucose intolerance in their offspring.     

Analyses of toxic metals and essential minerals in the hair of arizona children with autism and associated conditions, and their mothers

The objective of this study ws to assess the levels of 39 toxic metals and essential minerals in hair samples of children with autism spectrum disorders and their mothers compared to controls. Inductively coupled plasma-mass spectrometry was used to analyze the elemental content of the hair of children with autism spectrum disorders (n=51), a subset of their mothers (n=29), neurotypical children (n=40), and a subset of their mothers (n=25). All participants were recruited from Arizona. Iodine levels were 45% lower in the children with autism (p=0.005). Autistic children with pica had a 38% lower level of chromium (p=0.002). Autistic children with low muscle tone had very low levels of potassium (−66%, p=0.01) and high zinc (31%, p=0.01). The mothers of young children with autism had especially low levels of lithium (56% lower, p=0.005), and the young children (ages 3–6 yr) with autism also had low lithium (−30% p=0.04). Low iodine levels are consistent with previous reports of abnormal thyroid function, which likely affected development of speech and cognitive skills. Low lithium in the mothers likely caused low levels of lithium in the young children, which could have affected their neurological and immunological development. Further investigations of iodine, lithium, and other elements are warranted.     

Effect of Insulin and Energy Restriction on the Thermic Effect of Protein in Type 2 Diabetes Mellitus

Objective: The objective of this study was to test whether the thermic effect of oral protein is blunted in poorly controlled type 2 diabetes and is corrected by normalization of glycemia with insulin and 28 days of a very‐low‐energy diet. Research Methods and Procedures: Resting energy expenditure (REE) and the thermic effect of 90 g of oral protein were measured, using indirect calorimetry, in nine (five women and four men) obese diabetic people [weight, 108 ± 10 kg; waist circumference, 123 ± 8 cm; body mass index, 40 ± 3 kg/m²] who were hyperglycemic on day 8 or euglycemic with insulin on day 16 of a weight‐maintaining diet and euglycemic on day 28 of a very low energy diet (VLED). Results were compared with those of seven (six women and one man) weight‐ and body mass index‐matched obese nondiabetic subjects with a waist circumference of 111 ± 6 cm. Substrates and hormonal responses were determined concurrently. Results: Fasting glucose was normalized in the diabetic subjects with insulin from day 9 of VLED onward. Weight decreased in both groups by 9.9 ± 0.9 kg with VLED. REE was 8 ± 2% lower with insulin treatment and decreased by another 14 ± 3% with VLED in the diabetic and by 15 ± 1% in the nondiabetic subjects by week 4. After the protein meal, the thermic response was significantly (p < 0.05) less with hyperglycemia than with insulin‐induced euglycemia, as percentage above REE (15.3 ± 1.4 compared with 21.2 ± 1.5%), as percentage of the energy content of the meal (19.5 ± 1.5 compared with 25.2 ± 1.7%), as kilocalories per 405 minutes (86 ± 5 compared with 110 ± 7), and less than in nondiabetic obese controls (21.0 ± 2.2% above REE, 24.4 ± 1.7% of energy of meal). After the VLED, the thermic effect of protein was significantly higher in both groups only as percentage above REE. The initial glucagon response was greater with hyperglycemia compared with euglycemia and post‐VLED but not compared with the nondiabetic subjects. Hyperglycemia was associated with 21 ± 4% greater urinary urea nitrogen excretion and urinary glucose losses of 134 ± 50 mmol/d. Discussion: This study shows a blunted thermic effect of protein in obese hyperglycemic type 2 diabetic subjects compared with matched nondiabetic subjects that can be corrected with insulin‐ or energy restriction‐induced euglycemia.     

The time of determination of gynoparae and males in the bird cherry–oat aphid, Rhopalosiphum padi

Apterous exules of Rhopalosiphum padi which experienced short photoperiods only during the first half of their nymphal life all produced gynoparae which made up 57% of the offspring produced in the first 7 days of the mother's reproductive life. Short photoperiods during the second half of a mother's nymphal life did not induce the production of gynoparae. However, when short photoperiods were experienced throughout a mother's nymphal life significantly more gynoparae (82%) were produced. Ten per cent of the offspring of mothers that experienced short photoperiods only during their adult life developed into gynoparae. Of the offspring reared in short photoperiods, but born to mothers reared and kept in long photoperiods, 30% developed into gynoparae. When mothers were exposed to short photoperiods in their adult life and their offspring so treated, then 90% of the offspring developed into gynoparae. Males only occurred amongst the last offspring of mothers that experienced short photoperiods in either the first or the second half of their nymphal life.     

Maternal obesity induces gut inflammation and impairs gut epithelial barrier function in nonobese diabetic mice

Impairment of gut epithelial barrier function is a key predisposing factor for inflammatory bowel disease, type 1 diabetes (T1D) and related autoimmune diseases. We hypothesized that maternal obesity induces gut inflammation and impairs epithelial barrier function in the offspring of nonobese diabetic (NOD) mice. Four-week-old female NOD/ShiLtJ mice were fed with a control diet (CON; 10% energy from fat) or a high-fat diet (HFD; 60% energy from fat) for 8 weeks to induce obesity and then mated. During pregnancy and lactation, mice were maintained in their respective diets. After weaning, all offspring were fed the CON diet. At 16 weeks of age, female offspring were subjected to in vivo intestinal permeability test, and then ileum was sampled for biochemical analyses. Inflammasome mediators, activated caspase-1 and mature forms of interleukin (IL)-1β and IL-18 were enhanced in offspring of obese mothers, which was associated with elevated serum tumor necrosis factor α level and inflammatory mediators. Consistently, abundance of oxidative stress markers including catalase, peroxiredoxin-4 and superoxide dismutase 1 was heightened in offspring ileum (P<.05). Furthermore, offspring from obese mothers had a higher intestinal permeability. Morphologically, maternal obesity reduced villi/crypt ratio in the ileum of offspring gut. In conclusion, maternal obesity induced inflammation and impaired gut barrier function in offspring of NOD mice. The enhanced gut permeability in HFD offspring might predispose them to the development of T1D and other gut permeability-associated diseases.     

Consequence of omitting or adding a meal in man on body composition, food intake, and metabolism

Objective: To investigate in man the consequence on body composition and related biological and metabolic parameters of omitting or adding a meal. Research Methods and Procedures: Twenty‐four young normal‐weight male subjects were recruited, 12 usual four‐meal and 12 usual three‐meal eaters, differing only in the consumption of an afternoon meal. They omitted or added a fourth meal during a 28‐day habituation period and were asked to report their intake on three 3‐day occasions. Before and after this habituation period, subjects participated in a session with a time‐blinded procedure, and blood was collected continuously from lunch to the spontaneously requested dinner. Body composition, respiratory quotient, and biochemical parameters were measured in the late evening preceding each session. Results: Omitting a meal was followed by increases in fat mass (360 ± 115 grams, p < 0.05), late evening leptin concentration (20.7 ± 11.0%, p < 0.05), and respiratory quotient (3.7 ± 1.4%, p < 0.05). Increase in the percentage of dietary fat during the habituation period (+4.1 ± 2.0%, p < 0.05) was correlated with fat mass (r = 0.66, p < 0.05). Adding a meal had no effect, but, in both groups, the change in energy content at this fourth eating occasion was correlated with the change in adiposity. Discussion: Our results suggest that adiposity may increase when young lean male subjects switch from a four‐ to a three‐meal pattern by removing their usual afternoon meal. This effect could be partly mediated by a change in the macronutrient composition of the diet.     

What happens to offspring when parents are inbred,old or had a poor start in life? Evidence for sex‐specific parental effects

Parental effects on offspring performance have been attributed to many factors such as parental age, size and condition. However, we know little about how these different parental characteristics interact to determine parental effects, or the extent to which their effect on offspring depends on either the sex of the parent or that of the offspring. Here we experimentally tested for effects of variation in parents’ early diet and inbreeding levels, as well as effects of parental age, and for potential interactive effects of these three factors on key aspects of offspring development in the mosquitofish (Gambusia holbrooki). Older mothers produced offspring that were significantly smaller at birth. This negative effect of maternal age on offspring size was still evident at maturation as older mothers had smaller daughters, but not smaller sons. The daughters of older mothers did, however, reach maturity sooner. Paternal age did not affect offspring body size, but it had a complex effect on their sons’ relative genital size. When initially raised on a food‐restricted diet, older fathers sired sons with relatively smaller genitalia, but when fathers were initially raised on a control diet their sons had relatively larger genitalia. The inbreeding status of mothers and fathers had no significant effects on any of the measured offspring traits. Our results indicate that the manifestation of parental effects can be complex. It can vary with both parent and offspring sex; can change over an offspring's life; and is sometimes evident as an interaction between different parental traits. Understanding this complexity will be important to predict the role of parental effects in adaptation.     

Positive Maternal Attitude to the Family Eating Together Decreases the Risk of Adolescent Overweight

Objectives: To determine whether maternal attitude towards the family regularly eating together and maternal report of how often the family eat together are associated with adolescent offspring overweight. Research Methods and Procedures: A cross‐sectional mother‐child‐linked analysis was carried out using 14‐year follow‐up data from a population‐based prospective birth cohort of 3795 children (52% males) who were participants in the Mater‐University study of pregnancy, Brisbane, Australia. Maternal reports on family eating pattern reported at age 14 were used. Results: The prevalence of overweight at age 14 was 24.1% (95% confidence interval (CI), 22.3, 26.1) for males and 27.1% (CI, 25.1, 29.2) for females. The majority of mothers (78%) reported that the family ate together at least once a day, but only 43% reported that they felt that family eating together was important. The offspring of women who felt that the family eating together was not important had increased odds of being overweight at age 14 (odds ratio, 1.27; 95% CI, 1.05, 1.53) in age‐ and sex‐adjusted models. Adjustment for potential confounding factors had no substantive effect on the association. There was no association between maternal reports of how often the family actually did eat together and overweight at age 14 in the offspring. Discussion: These findings suggest that maternal attitude towards family eating patterns, but not maternal report of how often the family do eat together, are associated with childhood overweight status. Maternal attitude towards family eating (as opposed to a report of actual frequency at one time‐point) may reflect broader maternal influences (beyond family eating pattern) on their child's diet and eating patterns over a long time course.     

Emergence of insulin resistance in juvenile baboon offspring of mothers exposed to moderate maternal nutrient reduction

Developmental programming of postnatal pancreatic β-cell and peripheral insulin function by maternal nutrient reduction (MNR) has been extensively investigated in rodents and sheep, but no data exist from nonhuman primate offspring of MNR mothers. We hypothesized that moderate levels of MNR would result in developmental programming of postnatal β-cell function and peripheral insulin sensitivity that lead to emergence of a prediabetic state prior to puberty. Prepregnancy phenotype of 18 nonpregnant baboons was matched. During pregnancy and lactation 12 mothers ate chow ad libitum (controls), while six ate 70% of chow consumed by controls (weight-adjusted MNR). Weaned offspring ate normal chow. At 3.5 ± 0.18 yr (mean ± SE) in an intravenous glucose tolerance test, conscious, tethered MNR juvenile offspring (2 females and 4 males) showed increased fasting glucose (P < 0.04), fasting insulin (P < 0.04), and insulin area under the curve (AUC; P < 0.01) compared with controls (8 females and 4 males). Insulin AUC also increased following an arginine challenge (P < 0.02). Baseline homeostatic model assessment insulin β-cell sensitivity was greater in MNR offspring than controls (P < 0.03). In a hyperinsulinemic, euglycemic clamp, the glucose disposal rate decreased 26% in MNR offspring. Changes observed were not sex dependent. MNR in pregnancy and lactation programs offspring metabolic responses, increasing insulin resistance and β-cell responsiveness, resulting in emergence of an overall phenotype that would predispose to later life type-2 diabetes, especially, should other dietary challenges such as a Westernized diet be experienced.     

Inheritance of optimal foraging behaviour in Columbian ground squirrels

Summary I examined the potential inheritance of the ability of Columbian ground squirrels (Spermophilus columbianus) to select an optimal diet. I calculated the diet that would maximize daily energy intake for each of 21 adult females and their litters, using a linear programming optimization model for each individual. The absolute value of the difference between an individual's predicted optimal diet and observed diet (deviation from an optimal diet) was used as a measure of an individual's foraging ability. The foraging ability of individuals was consistent over time and in different foraging environments, so I considered foraging ability to be a potentially heritable trait.Inheritance was determined from correlations of mother and offspring foraging ability. I experimentally removed some mothers just as they weaned their offspring so that offspring could not be influenced by their mother while learning to forage, while leaving the other mothers to raise their litters normally. In both cases, offspring strongly resembled their mother in foraging ability. However, offspring with mothers absent exhibited significantly larger deviations from their optimal diet. Offspring with mothers absent appeared to imitate their mother's diet during lactation, and this tendency partially explained their greater deviation. Consequently, offspring appear to inherit the ability to forage optimally from their mother, perhaps through observational learning or imitation. There may also be a genetic basis to foraging ability, but uncontrolled maternal effects in the experiment prevent a proper test for it.     

Energy Intake and Meal Portions: Associations with BMI Percentile in U.S. Children

Objective: We examined relationships of eating patterns and reported energy intake (rEI) with BMI percentile in U.S. children. Research Methods and Procedures: Two 24‐hour dietary recalls from the Continuing Surveys of Food Intakes by Individuals 1994 to 1996 and 1998 (1005 boys, 990 girls) were averaged, and children were categorized into three age groups: 3 to 5 years (n = 1077), 6 to 11 years (n = 537), and 12 to 19 years (n = 381). Physiologically implausible reports due to reporting bias or abnormal intake (rEI outside ±18% to 23% of predicted energy requirements; pER) were identified. Results: rEI averaged 109 ± 34% and 100 ± 10% of pER in the total and plausible samples, respectively. EI was overreported more in younger children and underreported more in overweight older children. Children with plausible rEI (45.3% of sample) averaged 4.7 eating occasions/d, 589 kcal/meal, 223 kcal/snack, and 2038 kcal/d. rEI was not associated with BMI percentile in the total sample. In the plausible sample, rEI, meal portion size, and meal energy were positively associated with BMI percentile in boys 6 to 11 years and in children 12 to 19 years. No relationships were found in children 3 to 5 years and girls 6 to 11 years. Relationships were more consistent and stronger in the plausible compared with the total sample. Discussion: Excluding implausible dietary reports may be necessary for discerning dietary associations with BMI percentile. EI and meal, but not snack, patterns may play a quantitatively greater role in weight regulation as children age.     

Metabolic and Weight Loss Effects of Long‐Term Dietary Intervention in Obese Patients: Four‐Year Results

Objective: To investigate the contribution of meal and snack replacements for long‐term weight maintenance and risk factor reduction in obese patients. Research Methods and Procedures: Prospective, randomized, two‐arm, parallel intervention for 12 weeks followed by a prospective single‐arm 4‐year trial in a University Hospital clinic. One hundred patients, >18 years old and with a body mass index > 25 and ≤ 40 kg/m², were prescribed a 1200 to 1500 kcal/d control diet (Group A) or an isoenergetic diet, including two meal and snack replacements (vitamin‐ and mineral‐fortified shakes, soups, and bars) and one meal high in fruits and vegetables (Group B). Following a 3 months of weight loss, all patients were prescribed the same energy‐restricted diet (1200 to 1500 kcal) with one meal and one snack replacement for an additional 4 years. Results: All 100 patients were evaluated at 12 weeks. Mean percentage weight loss was 1.5 ± 0.4% and 7.8 ± 0.5% (mean ± SEM) for Groups A and B, respectively. At 12 weeks systolic blood pressure, plasma triacylglycerol, glucose, and insulin concentrations were significantly reduced in Group B, whereas no changes occurred in Group A. After 4 years, 75% of the patients were evaluated. Total mean weight loss was 3.2 ± 0.8% for Group A and 8.4 ± 0.8% (mean ± SEM) for Group B. Both groups showed significant improvement in blood glucose and insulin (p < 0.001), but only Group B showed significant improvement in triacylglycerol and systolic blood pressure compared to baseline values (p < 0.001). Discussion: Providing a structured meal plan via vitamin‐ and mineral‐fortified liquid meal replacements is a safe and effective dietary strategy for obese patients. Long‐term maintenance of weight loss with meal replacements can improve certain biomarkers of disease risk.     

Water Consumption Increases Weight Loss During a Hypocaloric Diet Intervention in Middle‐aged and Older Adults

Water consumption acutely reduces meal energy intake (EI) among middle‐aged and older adults. Our objectives were to determine if premeal water consumption facilitates weight loss among overweight/obese middle‐aged and older adults, and to determine if the ability of premeal water consumption to reduce meal EI is sustained after a 12‐week period of increased water consumption. Adults (n = 48; 55–75 years, BMI 25–40 kg/m²) were assigned to one of two groups: (i) hypocaloric diet + 500 ml water prior to each daily meal (water group), or (ii) hypocaloric diet alone (nonwater group). At baseline and week 12, each participant underwent two ad libitum test meals: (i) no preload (NP), and (ii) 500 ml water preload (WP). Meal EI was assessed at each test meal and body weight was assessed weekly for 12 weeks. Weight loss was ～2 kg greater in the water group than in the nonwater group, and the water group (β = ?0.87, P < 0.001) showed a 44% greater decline in weight over the 12 weeks than the nonwater group (β = ?0.60, P < 0.001). Test meal EI was lower in the WP than NP condition at baseline, but not at week 12 (baseline: WP 498 ± 25 kcal, NP 541 ± 27 kcal, P = 0.009; 12‐week: WP 480 ± 25 kcal, NP 506 ± 25 kcal, P = 0.069). Thus, when combined with a hypocaloric diet, consuming 500 ml water prior to each main meal leads to greater weight loss than a hypocaloric diet alone in middle‐aged and older adults. This may be due in part to an acute reduction in meal EI following water ingestion.     

Environmentally-based maternal effects: a hidden force in insect population dynamics?

Summary The nutritional environment of the parental generation of the polyphagous gypsy moth, Lymantria dispar, can significantly influence the growth and reproductive potential of the next generation through environmentally-based maternal effects. In the first experiment, members of the parental generation were reared on red oak trees (Quercus rubra L.) with known defoliation and phenolic levels. Diet in the offspring generation was homogeneous (synthetic diet). With genetic effects accounted for 1) offspring attained greater pupal weights when their mothers fed on trees with higher leaf damage levels, 2) daughters had a shorter prefeeding stage, a trait associated with dispersal tendency, when their mothers experienced higher condensed tannin levels, and 3) sons had lower pupal weights when their mothers experienced greater condensed tannin levels. In the second experiment, members of the parental generation were reared on either red or black oak (Q. velutina) trees. Offspring of each mother were divided among four diets: red oak, chestnut oak (Q. prinus L.), a standard synthetic diet, and a low-protein synthetic diet. The parental host species accounted for 24% of the variation in daughters' development time; offspring diet accounted for 52%. When mothers were reared on black oak rather than red oak, their offspring developed significantly faster when the F1 diet was chestnut oak. Environmentally-based maternal effects can significantly influence the expression of offspring dispersal potential, growth rate, and offspring fecundity. These traits contribute to natality and survival in natural populations and, hence, to population growth potential. Theoretical models of insect population dynamics demonstrate that the presence of a time delay in a density dependent response can induce destabilization. Maternal effects act on a time delay and may participate in the destabilization characteristic of outbreak species.