Program.cs

using System;
using Newtonsoft.Json;

String json = "{\"items\": [{\"name\": \"ground pork\", \"calories\": 668.2, \"serving_size_g\": 226.796, \"fat_total_g\": 47.4, \"fat_saturated_g\": 17.7, \"protein_g\": 57.8, \"sodium_mg\": 168, \"potassium_mg\": 508, \"cholesterol_mg\": 210, \"carbohydrates_total_g\": 0.0, \"fiber_g\": 0.0, \"sugar_g\": 0.0}]}";
Recipe_List rec = JsonConvert.DeserializeObject<Recipe_List>(json)!;
Console.WriteLine(rec.Items![0].Name);

Recipe_JSON.cs

using Newtonsoft.Json;

public class Recipe_JSON
{

    [JsonProperty("sugar_g")]
    public double Sugar { get; set; }


    [JsonProperty("fiber_g")]
    public double Fiber { get; set; }


    [JsonProperty("serving_size_g")]
    public double ServingSize { get; set; }


    [JsonProperty("sodium_mg")]
    public double Sodium { get; set; }


    [JsonProperty("name")]
    public string? Name { get; set; }


    [JsonProperty("potassium_mg")]
    public double Potassium { get; set; }


    [JsonProperty("fat_saturated_g")]
    public double SaturatedFat { get; set; }


    [JsonProperty("fat_total_g")]
    public double TotalFat { get; set; }


    [JsonProperty("calories")]
    public double Calories {  get; set; }


    [JsonProperty("cholesterol_mg")]
    public double Cholesterol { get; set; }


    [JsonProperty("protein_g")]
    public double Protein { get; set; }


    [JsonProperty("carbohydrates_total_g")]
    public double Carbs { get; set; }
}

Recipe_List.cs

using Newtonsoft.Json;

public class Recipe_List
{

    [JsonProperty("items")]
    public Recipe_JSON[]? Items { get; set; }

}