In this LAB note
Question · Hypothesis · Method · Results · What Failed · What We Learned · What Changed at MOMS
Question
If a Functional ingredient adds 3.8 grams of fat to a shake, why does the shake gain only 10 calories?
Hypothesis
We expected the slot to add energy. Fat carries 9 kcal per gram on the standard Atwater factors, so 3.8 extra grams of fat should add about 34 calories. If the gain came in far below that, we expected something else in the recipe to be leaving, and the likeliest candidate was carbohydrate, because our recipes appear to be solved to a calorie budget rather than built up from a fixed ingredient list.
Method
We split all 201 recipes in the MOMS recipe database by whether the Functional column holds anything: 124 do and 77 do not. For each group we averaged calories, protein, fat, carbohydrate and fiber, and summed the grams in the produce and protein slots. We repeated the split for recipes whose Functional ingredient is a tree nut (cashew, pecan, walnut, almond, pistachio or hazelnut; 50 recipes), for seeds (chia or flax; 41 recipes), for the 43 recipes whose Functional ingredient is neither, and for the Filling calorie label alone. Finally we looked for pairs from the same body type and week, within four calories of each other, where one has no Functional ingredient and the other has a nut. For the energy arithmetic we used the standard Atwater factors: 4 kcal per gram of protein and carbohydrate, 9 kcal per gram of fat. We checked those factors against Novotny, Gebauer and Baer (American Journal of Clinical Nutrition, 2012), who fed 0, 42 or 84 g/d of almonds and reported that Atwater factors overestimated the measured energy of almonds by 32 percent (4.6 kcal/g measured versus 6.0 to 6.1 predicted). That matters for the slot specifically, because most of it is nuts. We did not audit how the recipe sheet's calorie column is calculated, only whether its numbers are internally consistent with the factors.
Results
Recipes with a Functional ingredient (n = 124) average 378.8 kcal, 11.7 g fat, 37.0 g carbohydrate, 33.2 g protein and 7.5 g fiber. Recipes without one (n = 77) average 368.9 kcal, 7.8 g fat, 43.5 g carbohydrate, 32.8 g protein and 7.8 g fiber. The slot adds 3.8 g of fat, removes 6.5 g of carbohydrate, and moves calories by 9.9. The arithmetic closes: +3.8 g x 9 = +34 kcal, -6.5 g x 4 = -26 kcal, +0.4 g protein x 4 = +2 kcal, for a net of about +10. The carbohydrate leaves with the produce. Recipes with a Functional ingredient carry an average of 72 g of produce-slot food against 125 g without one, and 208 g of protein-slot food against 246 g. One matched pair shows it at the scale of a single glass. WY-W1-DETOX-019-V1 has no Functional ingredient (Beet 65 g, Apple 80.3 g, Carrot 68.2 g, Strawberry 120 g, Greek Yogurt 220 g, Tofu 40 g, Coconut Milk 195 ml, Maple Syrup 14.8 g) and lists 395.1 kcal, 8.0 g fat, 53.3 g carbohydrate, 9.0 g fiber and 30.9 g protein. WY-W1-DETOX-013-V1 puts Lemon 2.5 g and Cashew 7.5 g in the Functional slot (with Avocado 11.7 g, Black Beans 50 g, Black Sesame 5 g, Egg 27.5 g, Tofu 50 g, Greek Yogurt 110.7 g, Almond Milk 117 ml, Soy Milk 78 ml and Agave 6.5 g) and lists 393.3 kcal, 17.7 g fat, 28.3 g carbohydrate, 7.9 g fiber and 32.2 g protein. Fat is 9.7 g higher, carbohydrate is 25.0 g lower, calories are 1.8 lower, and the second shake has 278.5 g less produce-slot food. The ceiling is visible in both groups. The highest-calorie recipe without a Functional ingredient is 397.6 kcal and the highest with one is 399.9. None of the 201 recipes exceeds 400.
What Failed
The tidy story has three holes. First, the 10-calorie average hides a split. The 50 nut recipes average 390.7 kcal, 21.8 above the empty-slot group, with 5.1 g more fat and 5.9 g less carbohydrate. The 41 seed recipes average 383.9 kcal, 15.0 above. The 43 recipes whose Functional ingredient is neither a nut nor a seed average 363.4 kcal, 5.5 below. The slot is a swap for some ingredients and a small add for others. Second, the swap does not hold in the Filling label. Filling recipes with a Functional ingredient (n = 51) average 387.2 kcal against 373.6 for Filling recipes without one (n = 14), a gain of 13.6, so there the slot adds calories. Third, the slot is not assigned at random. Recipes that carry a Functional ingredient already differ by 53 g of produce and 38 g of protein-slot food, so we cannot say the ingredient caused the carbohydrate drop. Our Score does not settle it either: 15.2 with the slot versus 14.6 without, against a spread of about 1.9, and we do not claim the slot raises Score. Fiber slipped 0.3 g overall. And if nuts deliver roughly a third less energy than the Atwater factors predict, the true calories of the nut recipes may sit below the listed ones.
What We Learned
The Functional slot is a macronutrient swap, not a calorie add. Because every recipe is solved to a ceiling just under 400 kcal, a nut or seed that adds fat has to be paid for with carbohydrate, and in this database most of that carbohydrate comes out of the produce slot. The hidden variable is the calorie budget, not the ingredient. And the trade is uneven across ingredient types: nuts add about 22 calories, seeds about 15, and spices and lemon take away about 5.
What Changed at MOMS
We now review any Functional ingredient together with the produce slot that gives way for it. When a recipe gains a nut or seed, we check how many grams of produce it displaced and whether fiber held. We also plan to stop describing the Functional slot as an add-on in recipe copy, and to look at Filling-label recipes separately, where the slot adds calories instead of swapping them.
References
Novotny JA, Gebauer SK, Baer DJ. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. American Journal of Clinical Nutrition. 2012;96(2):296-301.
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