On Salad, Soup, and Success

[JeffN]

On Salad, Soup, and Success
Jeff Novick, MS, RDN

A concern I often hear is that people can’t follow my dietary recommendations because they think large quantities of salad are required as a way to successfully incorporate the principles of calorie density, which are important for both weight loss and weight maintenance. They say consuming such large amounts of salad takes too much time, too much money, and/or may cause digestive issues. Too often, this leads them to conclude that the principles of calorie density cannot be helpful to them.

Setting the Record Straight on Salad

Salads are not required for success. They can be very time consuming and expensive, which are often key issues for many. All of the time, energy and money spent on salads is not only unnecessary, it may not the best way to incorporate veggies into your daily diet. (The same applies equally to raw vegetables.)

While adding vegetables to a meal lowers the overall calorie density and is an important part of my recommendations, salad is not required. In fact, when we look at the research on this, the form of vegetables that lowered overall calorie density the most and was the most filling was not salads, but vegetable soup. (See references 1-10 below.)

Practical Tips on Soup

Soups can work in many ways, the same as you may be using raw veggies and/or salads in applying the principles of calorie density. Here are 3 simple tips:

1) Soups can be an effective pre-load to a meal:

Soups filled (mostly or entirely) with non-starchy vegetables can reduce the overall calorie density of a meal if consumed before the meal as a “pre-load.” Studies have shown that salad pre-loads reduced the overall calorie density for the meal by 7% for a smaller salad and 12% for a larger one (6), while soup preloads lowered the overall calorie density of the meal by 20% (5).

2) Soups can lower overall calorie density of the meal:

To help lower the calorie density of a meal, I recommend that up to 50% of your meal (by visual volume) be non-starchy vegetables. Soups can be effectively used for this strategy. For example, have a bowl of vegetable soup with a plate or rice and beans.

3) Soups can be the main meal:

Soups can also be the main meal. If they are main meals, make sure you make them hearty and also include plenty of starches (legumes, pulses, intact whole grains, starchy vegetables) in the soup.

Success!

After I posted this on the McDougall 10-Day Program FB page, someone added, “One of the big advantages I see to taking this route, is that it totally bypasses the excuse of ‘I can't find a salad dressing I like.’ Or in my personal case, ‘I cannot tolerate the items often recommended, such as lemon juice and vinegar.’”

With fall coming, this is a perfect time to incorporate warm, satiating soups into your lifestyle. They can be inexpensive, quick to prepare and soothing. So, if you are struggling with the time or the expense it would take to include large amounts of salads and raw vegetables, try a big bowl of vegetable soup instead.

In Health,
Jeff

[JeffN]

References

1) Soup consumption is associated with a lower dietary energy density and a better diet quality in US adults.
Br J Nutr. 2014 Apr 28;111(8):1474-80. doi: 10.1017/S0007114513003954. Epub 2014 Jan 2.

Abstract
Epidemiological studies have revealed that soup consumption is associated with a lower risk of obesity. Moreover, intervention studies have reported that soup consumption aids in body-weight management. However, little is known about mechanisms that can explain these findings. The objective of the present study was to investigate associations between soup consumption and daily energy intake, dietary energy density (ED), nutrient intake and diet quality. Adults aged 19-64 years who participated in the National Health and Nutrition Examination Surveys during 2003-8 were included in the study. Soup consumers were identified from the first dietary recall using the United States Department of Agriculture food codes and combination food type from the dietary data. Compared with non-consumers (n 9307), soup consumers (n 1291) had a lower body weight (P = 0.002), a lower waist circumference (P = 0.001) and a trend towards a lower total energy intake (P = 0.087). Soup consumption was associated with a lower dietary ED (P< 0.001); this was independent of whether data on beverage or water consumption were included. Diet quality, as measured by the Healthy Eating Index 2005, was significantly better in soup consumers (P = 0.008). Soup consumption was also associated with a reduced intake of total fat and an increased intake of protein, carbohydrate and dietary fibre, as well as several vitamins and minerals (P < 0.05 for all). However, it was also associated with a higher intake of Na (P < 0.001). The relationship between soup consumption and body weight could be due to a reduced dietary ED and an improved diet quality. Consumers need to pay attention to their Na intake and choose low-Na products for a healthier diet.


2) Salad and satiety. The effect of timing of salad consumption on meal energy intake
Appetite. Volume 58, Issue 1, February 2012, Pages 242-248
https://doi.org/10.1016/j.appet.2011.10.003Get rights and content

Abstract
In a previous study, consuming a fixed amount of low-energy-dense salad as a first course reduced meal energy intake. We investigated whether this effect depended on serving salad before rather than with the main course, or on compulsory rather than ad libitum consumption. On five occasions, 46 women consumed ad libitum a main course of pasta, accompanied four times by low-energy-dense salad (300 g; 100 kcal [418 kJ]). At two meals the salad was served 20 min before the pasta (once compulsory; once ad libitum), and at two meals the salad was served with the pasta (once compulsory; once ad libitum). Results showed that adding a fixed amount of salad to the meal reduced energy intake by 11% (57 ± 19 kcal [238 ± 79 kJ]). Ad libitum salad consumption was less than compulsory consumption and did not significantly affect energy intake. Across all participants, the timing of serving the salad did not significantly influence energy intake, but the effect of timing depended on participant scores for flexible dietary restraint. Consuming low-energy-dense salad before rather than with the main course increased vegetable consumption by 23%. To moderate energy intake, maximizing the amount of salad eaten may be more important than the timing of consumption.

Highlights

► Consuming a low-energy-dense salad at the start of a meal can reduce energy intake.
► In a crossover design, we compared serving a salad before or with the main course.
► Compulsory salad reduced meal energy intake by 11% regardless of when it was eaten.
► The effect of timing depended on participant scores for flexible dietary restraint.
► Maximizing salad intake was an effective strategy for reducing meal energy intake.


3) Soup Consumption Is Associated with a Reduced Risk of Overweight and Obesity but Not Metabolic Syndrome in US Adults: NHANES 2003–2006. PLoS ONE 8(9): e75630. doi:10.1371/journal.pone.0075630

Abstract
A limited number of studies have found that soup consumption is related to a lower risk of overweight and obesity in Asian and European populations, however, these studies do not provide a consistent picture regarding the association between soup consumption and markers of metabolic syndrome. To date, no study examining the relationship between soup and body weight or metabolic syndrome have been conducted in the US population. The present study used a sample of 4158 adults aged 19–64 who participated in the National Health and Nutrition Examination Survey between 2003 and 2006. The frequency of soup consumption was determined using a food frequency questionnaire. The weighted prevalence of soup consumption was 94%, with a seasonal variation in the frequency of soup consumption being found. Non-consumers of soup were at a higher risk of being overweight or obese (adjusted odds ratio=1.381, P=0.013), with a higher adjusted prevalence of reduced HDL cholesterol (adjusted odds ratio = 1.280, P = 0.045), but there was no association between soup consumption and metabolic syndrome (P=0.520). The frequency of soup consumption was inversely associated with covariate-adjusted body mass index and waist circumference (P,0.05), but not with biomarkers of metabolic syndrome, except for a lower fasting insulin level in frequent soup consumers (P = 0.022). Results from the present study suggest soup consumption is not associated with metabolic syndrome. However, there is an inverse relationship between soup consumption and body weight status in US adults, which support laboratory studies showing a potential benefit of soup consumption for body weight management.



4) Serving large portions of vegetable soup at the start of a meal affected children's energy and vegetable intake. Appetite. 2011 Aug;57(1):213-9. doi: 10.1016/j.appet.2011.04.024. Epub 2011 May 8.
http://www.ncbi.nlm.nih.gov/pubmed/21596073

Abstract
This study tested whether varying the portion of low-energy-dense vegetable soup served at the start of a meal affects meal energy and vegetable intakes in children. Subjects were 3- to 5-year-olds (31 boys and 41 girls) in daycare facilities. Using a crossover design, children were served lunch once a week for four weeks. On three occasions, different portions of tomato soup (150, 225, and 300 g) were served at the start of the meal, and on one occasion no soup was served. Children had 10 min to consume the soup before being served the main course. All foods were consumed ad libitum. The primary outcomes were soup intake as well as energy and vegetable intake at the main course. A mixed linear model tested the effect of soup portion size on intake. Serving any portion of soup reduced entrée energy intake compared with serving no soup, but total meal energy intake was only reduced when 150 g of soup was served. Increasing the portion size increased soup and vegetable intake. Serving low-energy-dense, vegetable soup as a first course is an effective strategy to reduce children's intake of a more energy-dense main entrée and increase vegetable consumption at the meal.


5) Soup preloads in a variety of forms reduce meal energy intake
Appetite. 2007 Nov; 49(3): 626–634.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2128765/

Abstract
Consuming soup can enhance satiety and reduce energy intake. Little is known about the influence on energy intake and satiety of varying the form of soup by altering the blending of ingredients. We tested the effects on meal intake of consuming different forms of soup as a preload: broth and vegetables served separately, chunky vegetable soup, chunky-pureed vegetable soup, or pureed vegetable soup. Normal-weight men and women (n = 60) came to the laboratory for lunch once a week for 5 weeks. Each week, one of four compulsory preloads, or no preload, was consumed prior to lunch. A test meal was consumed ad libitum 15 min after the soup was served. Results showed that consuming soup significantly reduced test meal intake and total meal energy intake (preload + test meal) compared to having no soup. When soup was consumed, subjects reduced meal energy intake by 20% (134+/-25 kcal; 561+/-105 kJ). The type of soup had no significant effect on test meal intake or total meal energy intake. Consuming a preloadof low-energy-dense soup, in a variety of forms, is one strategy for moderating energy intake in adults. PMID: 17574705



6) Salad and satiety: energy density and portion size of a first-course salad affect energy intake at lunch. Randomized controlled trial. Rolls BJ, et al. J Am Diet Assoc. 2004. Oct;104(10):1570-6.

Abstract
OBJECTIVE: We tested the effect on meal intake of varying the energy density and portion size of a compulsory first-course salad.
DESIGN: The study used a randomized crossover design.
SUBJECTS/SETTING: Forty-two women from the State College, PA, university community ate lunch in the laboratory once per week for 7 weeks.
INTERVENTION: Lunch comprised one of six first-course salads, or no salad in the control condition, followed by a main course of pasta. Subjects were required to consume the entire salad, but ate as much pasta as they wanted. The salads varied in energy density (0.33, 0.67, or 1.33 kcal/g) and portion size (150 or 300 g). The energy density of the salad was reduced by changing the amount and type of dressing and cheese.
MAIN OUTCOME MEASURES: Energy intake and ratings of hunger, satiety, and food characteristics were measured.
STATISTICAL ANALYSES PERFORMED: Outcomes were analyzed using a linear mixed model with repeated measures.
RESULTS: Compared with having no first course, consuming the low-energy-dense salads reduced meal energy intake (by 7% for the small portion and 12% for the large), and consuming the high-energy-dense salads increased intake (by 8% for the small portion and 17% for the large). When two salads with the same number of calories were compared, meal intake was decreased when the large portion of the lower-energy-dense salad was consumed.
CONCLUSIONS: Eating a low-energy-dense first course enhances satiety and reduces meal energy intake. Consuming a large portion of a low-energy-dense food at the start of a meal may be an effective strategy for weight management.



7) Water incorporated into a food but not served with a food decreases energy intake in lean women. Am J Clin Nutr. 1999 Oct;70(4):448-55. Rolls BJ1, Bell EA, Thorwart ML.
http://ajcn.nutrition.org/content/70/4/448.full

Abstract
BACKGROUND: Previous research showed that decreasing the energy density (kJ/g) of foods by adding water to them can lead to reductions in energy intake. Few studies have examined how water consumed as a beverage affects food intake.
OBJECTIVE: This study examined the effects of water, both served with a food and incorporated into a food, on satiety.
DESIGN: In a within-subjects design, 24 lean women consumed breakfast, lunch, and dinner in our laboratory 1 d/wk for 4 wk. Subjects received 1 of 3 isoenergetic (1128 kJ) preloads 17 min before lunch on 3 d and no preload on 1 d. The preloads consisted of 1) chicken rice casserole, 2) chicken rice casserole served with a glass of water (356 g), and 3) chicken rice soup. The soup contained the same ingredients (type and amount) as the casserole that was served with water.
RESULTS: Decreasing the energy density of and increasing the volume of the preload by adding water to it significantly increased fullness and reduced hunger and subsequent energy intake at lunch. The equivalent amount of water served as a beverage with a food did not affect satiety. Energy intake at lunch was 1209 +/- 125 kJ after the soup compared with 1657 +/- 148 and 1639 +/- 148 kJ after the casserole with and without water, respectively. Subjects did not compensate at dinner for this reduction in lunch intake.
CONCLUSION: Consuming foods with a high water content more effectively reduced subsequent energy intake than did drinking water with food. PMID: 10500012



8 ) The effect of soup on satiation.
Appetite. 1998 Apr;30(2):199-210.
http://www.ncbi.nlm.nih.gov/pubmed/9573453

Abstract
We compared the influence of three solid/liquid preloads to a no-preload condition given at lunchtime on hunger ratings and energy intake of the lunch and subsequent dinner in 12 lean and 10 overweight young men. The preloads (vegetables and water, strained vegetable soup, chunky soup) were of the same composition and volume but differed in distribution of nutrients between the liquid and the solid phases, and in the size of solid particles. Hunger ratings were reduced by the preloads; there was a significantly greater suppression of hunger after the chunky soup than after the vegetables and water. In both groups, the soups reduced energy intake at lunch, although the chunky soup had the most effect. In the overweight subjects, a reduced lunch intake was also followed by a reduced dinner intake. The benefit to weight control of large particles in soup should be evaluated.



9) Foods with different satiating effects in humans
Appetite. 1990 Oct;15(2):115-26.
Abstract
The aim of this study was to identify particular properties of foods that can affect satiety. Two levels (50 and 200 kcal) of three preloads (tomato soup, melon, cheese on crackers) were given just before two different second courses (macaroni and beef casserole, grilled cheese sandwiches), allowing us to examine the effects of caloric level, energy density, and sensory-specific satiety on food intake in normal weight, non-dieting males. Eating time and initial palatability ratings were held constant. Soup was found to reduce second course intake significantly more than the other preloads. This reduction could be partially accounted for by the low energy density of tomato soup; however, soup reduced intake more than the melon preload, which was matched for energy density. Sensory-specific satiety did not explain the satiating efficiency of the soup. Thus, during a meal, tomato soup is more satiating than the melon and cheese on crackers. Further studies are required to determine why these foods have different effects and to determine whether soup consumption can be beneficial in weight reduction programs.



10) The satiating efficiency of foods.
Physiol Behav. 1984 Feb;32(2):319-32.
http://www.ncbi.nlm.nih.gov/pubmed/6718557

Abstract
Experiments were undertaken to test the general hypothesis that some foods are more satiating than others, to find a mechanism for their differential satiating efficiencies, and to determine whether certain soups had a high enough satiating efficiency to recommend their addition to a meal as a way of reducing total caloric intake of that meal. In the first experiment it was found that intake of a test meal was lower after a large preload of tomato soup than after a small preload in women, but not in men. However, the total energy intake (soup plus test meal) was no less with meals which included the large soup preload than it was with meals that did not include a preload. Therefore adding a normal portion of tomato soup to a meal would not reduce its total energy intake. We noted the interesting incidental finding that total energy intake (i.e., preload plus test meal) of the meals which contained the larger amount of soup was less than the total energy intake of the meals which contained a combination of crackers , jelly, and juice. In the second experiment we confirmed this finding by showing that when equal weights of tomato soup preloads and a preload of crackers , cheese, and apple juice, which contains more energy, were given, total energy intake was less in meals which included soup. Therefore, substituting tomato soup for a more calorically dense first course could reduce total energy intake of that meal. In the third experiment, the hypothesis suggested by the second was confirmed. Two soups were more satiating than crackers , cheese, and juice. When two calorie levels were used for each preload, it was shown that calorie for calorie, these soups decreased intake of the test meal more than crackers , cheese, and juice. In the fourth experiment we showed that the mechanism for this differential satiating efficiency is not readily attributable to either bulk related factors or fat content. We suggest that the differential satiating efficiencies are related to differences in nutrient dispersion, orosensory cues, or temperature. Finally, reductions in intake were accompanied by reductions in the initial rate of eating and not by increases in the rate of deceleration. This reduction was small but consistent and suggests that foods which are more satiating reduce intake by decreasing desire to eat (i.e., hunger), not by accelerating the onset of meal termination (i.e., satiety). In fact the duration of meals was unaffected by the preloads.
PMID: 6718557